Id plan on having amp recapped at some point if you buy it. Ive read that electrolitic capacitors dry up, leak, swell after about 15 to 20 years. Probably factors such as cap quality, use, environment play a part.
Bought a Carver M400 amp and C4000 pre new in 1980.
Waited a bit too long, but had them recapped 40 years later. They were in storage about 10 years of that time. Definately needed it.