Excuse me.......under what provision of any law can that STG44 be "sold"? There isn't any precedence for it, either. Other people/organizations have found valuable WWII and WWI firearms and no exception was made for them.
The bottom line, in my opinion as a C&R collector for almost 20 years, is that the rifle is worth ..........zero......... period. It's simple. It's not registered and since it's not registered and there is no exclusions for it nor is there an amnesty going on, it is illegal to own and can not be made legal. There's a lot of precedence for this. Not too long ago remember the library in Nahant, MA that found a Maxim machine gun in full working order in their attic? They needed a lot of work on the building and discovered that Sgt. York had donated the Maxim to the library between the wars. It was then forgotten. Well, when rediscovered it was estimated to be worth $200k. It never got sold, however. ATF said no.
http://www.armytimes.com/news/2007/04/army_yorkgun_070429w/
The fact that the Hartford cops gave some 'reverence" to it is nice but that smg died the day after the last amnesty in 1968. Under Section 207(d) of the Gun Control Act of 1968, Congress authorized the Secretary of the Treasury to establish unlimited numbers of amnesty periods, not to exceed 90 days each, after publication of notice of his intention to do so in the Federal Register. A 30 day amnesty was declared in Nov./Dec., 1968, but none since. Every time another one has been suggested, the BATFE has objected. Why? Your guess is as good as mine. Imagine the numbers of firearms that would surface, become legal, and generate income to the owners, and ultimately the gubmint?
Anyway, at this point, that find might as well be a demilled fake because putting it into a museum is a mile away from seeing it back in. Too bad and the cops simply misspoke.
Rome