Where to begin research on this, folding leaf table?

I doubt we were still making tilt tops like that in the 40s, let alone the 70s. Need a close up of its mechanism.

 

nothing to report on the hinge ... so is it possible hinge is a non-original replacement, or blatantly faux antique from the 70s?

 

That's modern. Far too flimsy a construction to be older.

 

for what it's worth, Assuming those screws are original, Phillips head screws have been on the scene only since the late 1930's, and not until later in furniture.