Search AvSim or FlightSim for "Gordon Perry." He made quite a few Air Force Base sceneries, including some like Loring AFB that are no longer military bases.
His bases aren't particularly intended to be 1950s era, but they look a lot better than the stock bases. At least the hangars look like hangars and not like office buildings.
I don't know how accurate they are, or how much the various bases have changed since the fifties, but again, they've gotta be more realistic than the stock scenery. He says in his ReadMe files that they don't pretend to be perfect, but I don't think they're very far off. One thing I don't like so much about some of his sceneries is that he has the multi-LOD buildings set so that they pop into visibility from closer in than they should, at least on my system. That can be somewhat annoying.
I also found that the AFCAD file for Westover, my home MATS & SAC base in "Flight Simulator 1954 - A Half Century of Flight" was off by quite a bit; the ramps and taxiways didn't match up with where the buildings and ground features were. I had to rework the AFCAD. They seem much better at the other fields I've looked at, like Loring and Otis. Maybe only Westover had a poor AFCAD file. If you decide to install his Westover, drop me a PM and I'll send you a copy of my revised AFCAD file.