Interesting topic,
not sure what is the oldest we can find but here one I found which is quite old.
Mostly I seem to find medals. Here a medal from roughly 1660 from the city of Wroclaw/Breslau nowadays Poland depicting the birth of Jesus
Some show also darker times of history, Christmas 1915. Many Chrismas themed medals actually exist that were minted during WW1
This below medal from Hamburg telling about the terrible flood that happened on Christmas eve
Coins diretly I didn't find anything much directly mentioning Christmas, here is one but not very old
If you like coins, medals and tokens with ship motives follow my new instagram account with regular updates @numisnautiker
From time to time I sell some coins on Ebay make sure to follow me @apuking on Ebay.