If it was made for JFK outside the factory, there may be a chance (if it can be found and examined) that the engraver may have signed his work (either overtly or covertly.) Knowing the engraver might help the search somewhat. I would tend to doubt that the Kennedys, even with the anti-gun stance Teddy's branch took in later years, would have let such a historical piece get away, rather keeping it for one of the museums or other displays to honor his memory. It's not like Jackie needed the money and had to pawn it or have a garage sale.

It seems I've heard about an M-1 (Garand? Carbine?) that was ordered from a well-known address on Pennsylvania Ave in DC. When the folks at the old DCM saw the order, a very nice "presentation grade" version of the rifle was sent along forthwith. I'm not sure where that gun ended up, but I'm guessing there is a well documented trail for it. Anything that is reliably connected to JFK commands attention wherever it ends up!

Froggie