Higgins94

hi, have been facinated by gold + silver since i was a child and metal in general has played a big part in my life (im a welder + keen metal detectorist) i have for the last couple of years been messing around with a homemade foundry, i have cast a few 1oz sterling silver bars, a couple of 999 gold bars and countless aluminium ingots, i have also done some refining (also very interested in chemistry) - i love it, it has become somewhat of an addiction haha. how would i go about turning it into an occupation? if i wanted to sell bullion that i have cast would i be required to register with any organisation? would my bullion need to be tested for quality ? or could i just punch it with a serial number, fineness mark and logo and sell ? any info would be greatly appreciated cheers