I wonder about some of the stuff mentioned by early respondents to this ancient thread.
And I don’t know what is meant by “restored”. If it means “maintained” or “repaired”, then for me the answer is I have many items older than that that haven’t been restored. If it means recapping )except speakers) or updating things like op-amps, then I haven’t done any of that. If it means bringing something bought dead back to pristine, then I don’t do that, either.
I did replace a couple of relays in my 35-year-old SAE equalizer. Nothing older than that has gone unserviced, and that includes a Thorens TT, and many cleaned pots. The only capacitors I’ve replaced were in my 42-year-old Advent speakers, and I think only one of four actually needed it. (Of course, all the foam has been replaced, and several damaged drivers, too). All belts that predate about 2000 have been replaced. I don’t put any of that in the category of “restoration”.
Rick “whose equipment was all bought approximately working and then maintained” Denney