I thought I would add a point to the rest of this discussion:
Acoustic guitars of the fourties and fifties and electric guitars of the fifties and sixties (along with their amps) defined for most of us what those instrument types should sound like. Our idea of good tone was dictated by Teles, Strats, Pauls, D-28s and J-45s. If other guitars had been popular at the time our idea of good tone might be very different. Those instruments were built by different craftsmen with different processes to (in most cases) different designs using somewhat different materials than those made today. There is no way to factor out all these things so we can judge what difference age makes. Shoot, pull two guitars of the same make and model off the rack and they may well sound very different.