With so many coins depicted on one medal, you really need to have a huge piece.

Celebrating 660 years is a little strange though, so making this a medal and not a coin is fine ...
A piece from Germany - 50 Years Deutsche Mark, with 1, 2 and 5 DM coins:

Austria - 800 Years Vienna Mint, showing the 13c silver Vienna Pfennig:

And one from the GDR - 700 Years of Minting in Berlin:

This one shows an "Ewiger Pfennig" coin from the early years of the mint. Such coins (denarius perpetuus, eternal penny) were, at least in theory, safe from being recoined ...
Christian