Actually, I have listened to those older receivers with the 680-Ohm headphone output inpedance. Those receivers sound utterly unlistenable with any modern low-impedance headphones whatsoever (the impedances were severely mismatched, with the headphone's own impedance being far lower than the headphone jack impedance). Those receivers really require headphones that never existed at all - those with a nominal impedance of greater than 47 kilohms (>47,000 Ohms) just to sound even acceptable to my ears. But then again, modern headphones are really designed for newer gear with a near-zero-Ohm output impedance, with their relatively elevated bass response (compared to those early ultra-high-impedance 2,000-Ohm headphones that delivered virtually no real bass response whatsoever - their entire bottom end is severely recessed to compensate for the ultra-high output impedances of the day). Try plugging a modern headphone into such a vintage transistorized receiver, and it will sound very similar to the Beats Solo when the latter is plugged into the average low-output-impedance headphone amp. And many high-impedance headphone outs do not lower the impedance at all even with low-impedance headphones. That results in a sound that's extremely loose, severely distorted and almost completely uncontrolled.
By the way, the receivers that you have listened to that are "good" have valve (tube) amps. It's the transistorized (solid state) amps with high output impedances that you have to watch out for.
And among the OP's receivers, the vintage Fisher receiver has the best chance of sounding good with decent headphones. All three of the others were manufactured after the receiver manufacturers started cutting corners on headphone out quality (which began some time in the 1970s).