The item you describe is a plaque, made for use at the famous Monte-Carlo Casino in Monaco.
You'll see it listed on this page, under "Plaques - Older Currency"
http://www.themogh.org/cg_chip2.php?id=mcmcs1&p=00000001000000000#10

The value is in French Francs, before they were devalued, and then replaced by the Euro.
Not sure of the date -- could be 1930's (pre-war), but also may be post-WWII.

A number of these plaques were placed in lucite, because the early-plastic material can become brittle and flake, warp or even disintegrate.

As to value, they are fairly common, though still an interesting historical piece. I'd say in the $25 to $50 range, perhaps a bit more if the plaque inside is in very nice condition.

Hope you enjoy it.