I have a 12 sided thrupenny bit and a silver sixpence on a key ring. I know it's an offence to deface a coin of the realm but don't think anyone will come knocking at my door after all these years!
Blimey that's expensive! I used to charge £1 for three thruppenny bits and £1 for one silver coin on the markets. (That silver one has been cleaned - something you should never do - let the buyer decide what condition it stays in).
askyourgran, they look completely different. Mine is a 1950's set, my uncle used to work at the Mint and each year so many sets were made available to employees to purchase. They took it in turns to be allowed to purchase. They aren't the same as the bags the Queen gives, they are four coins in a little red fitted case. They aren't for sale. :)