Ah, well, now things can get interesting, as there were different types of threaded risers and posts used back in that era (70+ years back?). Some types encorporated nylon pieces under the post, for instance. And the actual poppets (the spring loaded bit inside the post that you can see the head) are kinda all over the place as to length and head diameter.
But, bottom line, if these kegs came with ball lock posts they'll mate with today's ball lock quick disconnects; same would apply if they sport pin lock posts. But either type posts may look quite different from more recent vintage fittings (check out John Woods keg posts, for instance)...
Cheers!