How well was this restoration process ?
Normally, solid state devices and resistors (except constantly moving pots, like a volume control) do not "age" significantly over time, unless they have been stressed and exposed to voltages & currents very close to their limits and/or exposed to heat.
Having said that ALL electrolytic caps, especially manufactured long time ago, WILL fail and some pretty catastrophically.
If you are sure that the restoration was made by a very reliable establishment, AND that the amp was not previously abused (used at max levels of its capacity very often) then the old amp should be just as good.
My worry however with old amps is always whether any of the output bipolar (most old amps has bipolar output stages) devices may fail (for whatever reason, typically too much heat) and destroy your speakers if there is no speaker protection circuit (or it does not function properly).
Normally, solid state devices and resistors (except constantly moving pots, like a volume control) do not "age" significantly over time, unless they have been stressed and exposed to voltages & currents very close to their limits and/or exposed to heat.
Having said that ALL electrolytic caps, especially manufactured long time ago, WILL fail and some pretty catastrophically.
If you are sure that the restoration was made by a very reliable establishment, AND that the amp was not previously abused (used at max levels of its capacity very often) then the old amp should be just as good.
My worry however with old amps is always whether any of the output bipolar (most old amps has bipolar output stages) devices may fail (for whatever reason, typically too much heat) and destroy your speakers if there is no speaker protection circuit (or it does not function properly).