All these amps were excellent designs for their days but many of them had negatives too. Parts are way better today(except possibly NOS tubes) and power supplies which are the true heart of an amplifier are way stronger today. Plus I'd never get near a non-linear single ended amp(Ongaku) that can't even produce a proper sine wave into a load(the negative half is not the same as the positive hald and that's endemic in singled ended topology).
Perhaps though we got more per dollar then(even with inflation figured in) in the old days given the zillion dollar costs of many of today's amps. And I did own a Stereo 70 and 1st generation ARC amps(mu Dual 70 was by far the least reliable amp I ever owned).