"What benefit does
this alleged balancing act have for the user? Too many unanswered
questions."

Anything too acidic or alkaline would be bad. However that doesn't mean something with the "proper" Ph for skin will be exactly right for this.

Of course if rinsed thoroughly anything from 6 to 8 should be just fine.

"The best example is pH balanced shampoo. What it does is suds only
over a very narrow range of pH. I don't recall the numbers, but it
specifically avoids the typically pH=5.5 of skin so that it does *NOT*
suds when first applied. Only after dilution with water, or a 2nd
application does the pH of the mix increase to roughly a neutral pH=7,
where it will produce suds. The obvious result is that users use
twice as much shampoo as they would with one that would suds at any pH
value. I suspect that hand and dishwashing soap may be similar, but I
haven't bothered to check.
"

Very interesting.

"Leave the rest alone as I assume that all the electrolytics
are bad and that it will need disassembly to replace those anyway.
"

You wouldn't believe how long some of those old caps can last. When was the 561A made ? I had to only replace one. I had to replace one in my 7603.