To what end? Is it an estate thing, or just for the heck of it.
You may have a problem in that a lot of the European stuff is not as well known here, and there's no "established" market for them.
If you post some details ( gauge, maker, etc) and pix, you may be able to get a ballpark.
If you're looking for a "what can I sell it for" number, go see what KTP will put on the counter....it will be a low end, but realistic figure.
Also, if it's a 16, make sure to check the chambers, in case they're "short", meaning 2 9/16"