That's a pretty silver set. Not my collecting area, but artistic value + precious metal value.

In case you don't get interest here, there's a whole collectible area for Duck Stamps. Again, not my area of collecting, but I think there are serious collectors for duck stamps, and if you can find a contact for such collectors (a club or website, etc.), someone there may have interest. eBay has a whole category of them too.

Just a thought, in case you weren't aware of duck stamps. See:
https://www.fws.gov/service/duck-stamps