i am curious if there is a specific name or category for coins or medals etc that use an existing coin as the flan / planchet?
a few monthes back I came across (found it in a random bulk
ebay lot that I had purchased) this fraternity coin that had been "minted" using an
IHC as the flan:


now I have come across this one (just bought it on
ebay):


i also remember seeing one other similiar fraternity type weeks ago (
ebay), as well as this one:


the gun one is still up on
ebay, not really of interest (just too modern) but it is in similiar style to the others, question is what are these called?