Flight of the Intruder, by Spectrum Holobyte is the only realistic flight sim I can think of in the Vietnam era.
It was a combination job between SH and Rowan iirc. They also made Battle of Britain (WW2) and Mig Alley (Korean War.)
True, Falcon includes Korea but it's far more modernized. Still, dropping GBUs on Pongyang has it's benefits.