I figure I'll just clean it up. It's got some old, dried paint in it, the barrel clamp screw has been replaced by a bolt, and somebody took off the rear sight in order to mount some kind of red-dot base. (The sight helps keep the linkage rod in place.)
The 20-ounce tank is missing it's burst disc, too. I have a literal pile of those, so I'm not gonna waste a new disc on it.
So it'll likely just get added to the rest of my wall-hangers.