It looks to me like it may be one of these -- posted here in the past depicting Holy Roman Emperor Maximilianus/Maximilian I.
http://www.treasurenet.com/forums/what/396159-need-id-help-friend-columbus-token-souvenier.html
Antique 23mm Austria Brass Button Maximilianus 1493 Pot Max Inv Caes | eBay
Antique Set of 3 Maximilianus 1493 Pot Max Inv Caes Metal Buttons 3 4" 18 4mm | eBay
Yes I think it is the same. It is still a bit of a mystery though. I haven't been able to find out why or when the design came into favor or what prompted it to be made into the buttons and the pieces like you found.