I can't help, but there are several collectors of 'Ancients' that seem to go for medieval coins...hopefully, a few will notice this thread and respond...
Not really into these, but it seems not to be to difficult ? First, on these types i try to find some orientation by finding the title of the ruler. Which is often Rex or Dux. With some guessing i see DUX starting from about 4 o'clock on your upper pic. Before the title should be a name, which i can't read. After the title is what he is ruler of. Again with some guessing i read STETTIN. Now Stettin used to be a German city in the Duchy of Pommern. The central element of this side is a Griffin. Google tells me the coat of arms of the Dukes of Pommern is a Griffin. So we are at the right track. In 1505 the name of the ruler was Bogislaus. The last letters might fit with whats before Dux. Again some googling shows there is a Shilling issued under Bogislaus X with on the reverse the shield of Rugen on a long cross. And that again fits with your coin. So this is a Shilling of Stettin mint in Pommern, issued under Bogislaus X.
Credit goes to @THCoins - I want to share this webpage with you - http://agoraauctions.com/listing/viewdetail/21611
The one shown by Paddyman is a similar, but not an identical type. Observe that the legend on the lion side of the opening post coin in no way can read "Moneta Nova Damm". Instead it is likely "Mone-Nova-Stet-in 1505". So this is Stettin mint. Found that this one has no Frey reference number, but it is Dannenberg 389.
