"Don't fix it if it's not broken" is my instinct. Generally, I can tell by looking at ripple with a 'scope if capacitance is insufficient.

Finding a defective solder joint is much more satisfying than a speculative replacement of caps which might not have exercised the bad joint.

Cheers!

In the end I had 4 newer caps laying around, plus the Original amp called for a massive bank, so I went ahead upgraded. Thanks all.