We had a pair of Volcanics go through the shop a few years ago. The new owner was determined to shoot it again, we just suggested he check with the Cartridge Club guys at the gun shows. I don't know if he ever figured out how to make Volcanic ammo. We had both calibers from an estate sale for awhile.
Funny thing. If somebody else has something uncommon to sell, it's rare and valuable. If you have the same item, people claim you can't give them away.