what will be the best old CLASSIC amp to rebuild.

I also agree that budget is not a concern when you want
the best of best. I have two Gibson SG 1970's one with
p-90 and other the luxe with PÄF and stereo output very
very rare. I just saw an other one SG like mine in stereo.

Nothing can compare a vintage instrument regarding the
sound quality same a custom shop at $3000 will not be able
to emulate a old wood vintage sound. In high end audio it
the same very high quality equipment can't be emulate you
have to paid for.And we paid for because we love music.

Thank again to share your experience.

If the amplifier is for the AR3 speakers you mentioned in an earlier post I suggest that you refurbish the speakers first, before chasing after amplifiers.

The speaker crossover parts should be evaluated and replaced as needed and the woofer surrounds will most likely require re-doping in order to properly re-seal the speakers and bring them up to spec.

This is a really great idea to restore the AR 3 but if i
have not yet consering this question is just because i
do'nt know who is qualify to made a great job on the AR 3
in my area... Some of the best AR specialist are in the USA.

Searching the right tech will be my priority to achieve
this goal. The power amp was redone by a tech and the right
chanel hum and the tweeter do'nt work anymore on my right
AR 3 speaker... Not a good experience.

Same if the AR 3 was my best score on thrift store as i
paid them only $10 for the pair now if they are broken
because of a tech i feel like i have not up grade my
system....

Accuphase E202 speaks for itself.
Fully restored unit can be purchased at $800 that will stay on top of most modern priced upto $2...3k.

QUAD 303