Numis65

You could always contact an online coin magazine in the US to see if there have been similar complaints with our American cousins ?

I would not totally give up on this at this stage.  Whilst it may be a longshot,if you have a photo of the coin that was submitted to NGC and it had no corrosion on it then and came back with it , then on the face of it , this will have happened whilst they had it and they owe you a duty of care in handling it. You , or if it was submitted through a dealer, the submitter should I suggest write to the CEO of NGC in a measured and unhostile tone, expressing your/their extreme disappointment at what has happened , that you have used them a lot satisfactorily in the past  (if that is the case)and saying that you expect to be reimbursed for the damage that has been caused to the coin whilst it was with them and that they have not complied with their duty of care whilst it was with them.
They will obviously resist and blame anyone else they can and assuming that they respond negatively to your first approach , I would suggest following this up with a threat to draw attention to what has occurred with the coin media, which you might eventually want to follow through on if they do not play ball. 
As I say this is a longshot but for the sake of a few letters/emails it may be worth trying. 
In terms of what they might eventually offer you , if at all, I guess that it they will not give you the resale value but might give you what you paid for it.
You could also at the same time contact the RM as a customer of their's and ask them what they think might have caused the issue given that they have metallurgists working for them.
A friendly dealer eg @ Lawrence Chard , might have a better suggestion!
Good luck

Could these burn marks be caused by some sort of coating the RM is putting on the silver coins to minimize milk spotting?  Maybe when NGC encapsulates the coins in the slabs they use a heat process that is burning the coating?

I would not totally give up on this at this stage.  Whilst it may be a longshot,if you have a photo of the coin that was submitted to NGC and it had no corrosion on it then and came back with it , then on the face of it , this will have happened whilst they had it and they owe you a duty of care in handling it. You , or if it was submitted through a dealer, the submitter should I suggest write to the CEO of NGC in a measured and unhostile tone, expressing your/their extreme disappointment at what has happened , that you have used them a lot satisfactorily in the past  (if that is the case)and saying that you expect to be reimbursed for the damage that has been caused to the coin whilst it was with them and that they have not complied with their duty of care whilst it was with them.
They will obviously resist and blame anyone else they can and assuming that they respond negatively to your first approach , I would suggest following this up with a threat to draw attention to what has occurred with the coin media, which you might eventually want to follow through on if they do not play ball. 
As I say this is a longshot but for the sake of a few letters/emails it may be worth trying. 
In terms of what they might eventually offer you , if at all, I guess that it they will not give you the resale value but might give you what you paid for it.
You could also at the same time contact the RM as a customer of their's and ask them what they think might have caused the issue given that they have metallurgists working for them.
A friendly dealer eg @ Lawrence Chard , might have a better suggestion!
Good luck

I would not totally give up on this at this stage.  Whilst it may be a longshot,if you have a photo of the coin that was submitted to NGC and it had no corrosion on it then and came back with it , then on the face of it , this will have happened whilst they had it and they owe you a duty of care in handling it. You , or if it was submitted through a dealer, the submitter should I suggest write to the CEO of NGC in a measured and unhostile tone, expressing your/their extreme disappointment at what has happened , that you have used them a lot satisfactorily in the past  (if that is the case)and saying that you expect to be reimbursed for the damage that has been caused to the coin whilst it was with them and that they have not complied with their duty of care whilst it was with them.
They will obviously resist and blame anyone else they can and assuming that they respond negatively to your first approach , I would suggest following this up with a threat to draw attention to what has occurred with the coin media, which you might eventually want to follow through on if they do not play ball. 
As I say this is a longshot but for the sake of a few letters/emails it may be worth trying. 
In terms of what they might eventually offer you , if at all, I guess that it they will not give you the resale value but might give you what you paid for it.
You could also at the same time contact the RM as a customer of their's and ask them what they think might have caused the issue given that they have metallurgists working for them.
A friendly dealer eg @ Lawrence Chard , might have a better suggestion!
Good luck

Got my portrait crown today.  Absolutely beautiful, and it looks great to me.  I had little doubt since I bought it from a dealer.  I believe they do look these over prior to shipping them.  The capsule was intact and perfectly embedded in the case.  The coin was nicely shipped in protective packaging.  Of course, I had to pay more than the RRP, but sometimes the peace of mind of not having to deal with the RM may be worth it.

Not everyone can get an issue at RRP.  Some people can't get a coin when they go on sale, and others may get a high queue number and the coin sells out before they can buy it.  It happens all the time.  So, if someone misses a coin and really wants it, they do not have much choice but to buy it from a dealer or flipper at more than RRP.  Also, some collectors refuse to deal the stress and nerves that go with the RM's queues, and instead prefer the less stress of buying from a dealer.  This is why dealers and flippers exist....and thrive.

Its very interesting to compare the posts on the early pages of this subject when people were  wondering whether or not to go for these coins  and whether they would prove a good buy ,to those more recently . Maybe a lesson to all of us there. 

Results TCC39
TCC37 -> TCC38  -> TCC39  all NGC unless otherwise mentioned
3G 2oz silver PF70 4k -> 2.3k -> 1.9K
(3G 2oz silver PF69 N/A -> 1.2k -> 1.25k)
3G 2oz gold PF70 41k -> 30k -> 21k
3G 2oz gold PF69 29k -> 16.5k -> 16.5k*  (* PGGS)
Perhaps interestingly PCGS 3G silver 2oz fetched 2.3k whereas the NGC equivalent got 1.9k.
 

Recording just for posterity.. also noteworthy silver 2oz Una PF70 managed to hold 6k. 😇
So... quickly comparing TCC37 -> TCC38 (all NGC):
3G 2oz silver PF70 4k -> 2.3k
(3G 2oz silver PF69 N/A -> 1.2k)
3G 2oz gold PF70 41k -> 30k
3G 2oz gold PF69 29k -> 16.5k
 

Looking at the results it seems that prices have softened for the larger Silver 3G  particularly the 1 Kilo but the 20z held up reasonably well

Looking at the results it seems that prices have softened for the larger Silver 3G  particularly the 1 Kilo but the 20z held up reasonably well

Fully agree I don't mind anyone making bit but there seems some real cut-throat people in the coin industry 
Most are decent a lot on here are great but then there are some that would take as much as they can
I don't work that say and won't deal with anyone that does 

Absolutely, it's not just 2 oz's of silver for sale, it's much more than that.
That value is the historical aspect and the origins from where it was minted.
Really sought after coin.
Don't sell for a 'cheap as chips' price!

I don't blame you,it sounds like at least a potential 100% profit margin for them .

I don't blame you,it sounds like at least a potential 100% profit margin for them .

I don't blame you,it sounds like at least a potential 100% profit margin for them .

@MikeG1978.  The perception is indeed, that people are flocking to sell these coins but search terms on Ebay of 'Three Graces Silver' say different.  
The results, for me anyway, were surprising in terms of what is actually available for sale, I was surprised of how few Royal Mint 2oz coins are for sale but more surprised by the amount of larger denomination coins that are available:
 
2oz Royal Mint:  21
5oz Royal Mint: 8
10oz Royal Mint: 3
1Kg Royal mint: 4
 
In terms of the knock off Alderney:
2oz Alderney: 13
5oz Alderney: 3
 
I really do need to get a life! 🤯

Thanks will give them a call tomorrow to see what they would offer. There is a balance to be had. 
If they offer what I think is a pragmatic price, or indeed are willing to buy, i will likely sell it.
If not, will keep a hold of it for the longer term.

You could try one of the dealers like Chard or the London Coin Company but obviously they need to turn a profit,  at least it would give you an indication . Otherwise ebay would give you the quickest return. Whether to sell now  or not is very subjective -the old "fear versus greed "conundrum (not that I am suggesting that you are either!) Personally I am more on the former and would rather take a smaller turn now than hold out for a bigger one in the future which may or may not materialise. As has been pointed out there are going to be an awful lot of PF 70s around which will affect the price downwards in the short to medium term, although there may be a renewal of interest when the next Great Engravers coin is released, provided that issue a success. Good luck with whatever you decide to do. 

think there will be a flood of 70s hitting the market when the bulk of them return from Trumpland
Only so many will be allowed in these coin auction sales each time so overspill will appear on FleaBay 
are there 900 collectors around the world willing to pay £4k ??? doubt it personally
Dont think it will be like for like comparison for the Una & Lion for values in the early days personally

I would take it out of its slab and enjoy it as a thing of beauty. 

I would take it out of its slab and enjoy it as a thing of beauty. 

I would take it out of its slab and enjoy it as a thing of beauty. 

I would take it out of its slab and enjoy it as a thing of beauty.