I don't think leaving the old electrolytic caps in place is the solution. First, the jantzens ( when Tara cables not used), sounds far superior than the old caps being used with the Tara cables. So if I was going to throw my hands up , I would keep the jantzens and hunt for cables that didn't give me issue's. I tried those belden 5000 cables and didn't have issues and it sounded pretty good.
Also this hasn't been driving me crazy, I've learned a lot and have enjoyed the project.
I'm going to buy that meter test those caps, make sure there all good, and try and buy resistors that compensate for any disparity.
And if that does nothing, and I'm ready to give up, then I'll try different cables till I get the sound like I know it's supposed to be.
That's the plan, but for now I've gotta move, so I'll be on a little break for a week or two