babs,
as a precaution, i'd suggest that you bench test the electrolytic caps that you will substitute for the bad ones. in the lab, i'd always use a suitable power supply, current limiting resistor, bleed resistor and cover the test component with a pickle bucket. if the caps are weak, you'll want to know about it before you install them and they spew electrolyte all over the circuit board.
since electrolytic capacitor technology has gotten better since this old amp was built, you can select low esm, low inductance caps wired into capacitive "banks" to replace those big, ugly, noisy ones. the new ones handle in-rush currents much better and will really increase the stability of the amp's power supply, not to mention make it much "punchier."
you'd be surprised at how many times i've proven aando peraandi's theoretical "noise emitting capacitor" model - screw up and your new caps will explode with a loud pop.
the outgrowth of peraandi's continued research gave birth to the "confetti generator" - that can be experienced by connecting a high current power supply to the capacitor in reverse polarity.
best regards, tube