Ed, If you like the way the Sophias sound w/ the ML 20.5s, you're not going to find better ss amps for anywhere near $8K, which is what the 20.5 + refurb. at ML would be worth max. Unless you want to buy a used pair of ML 33Hs for ~$10K, or maybe a DarTZeel for what? $30K?
So I say door #1. Have it done right at ML, before they lose THEIR service manuals. They'll really go over them with a FTC, and probably replace a lot of little parts too. You'll get a limited warranty on the new parts, I believe. And I think they're better than most on meeting their time estimates. Also you might ask them if, while they're at it, they'd install some proper 5-way speaker binding posts and replace the Camac inputs w/ RCAs! A lot of 20.5 owners have had this done (although I don't know if it was done at ML.)
So I say door #1. Have it done right at ML, before they lose THEIR service manuals. They'll really go over them with a FTC, and probably replace a lot of little parts too. You'll get a limited warranty on the new parts, I believe. And I think they're better than most on meeting their time estimates. Also you might ask them if, while they're at it, they'd install some proper 5-way speaker binding posts and replace the Camac inputs w/ RCAs! A lot of 20.5 owners have had this done (although I don't know if it was done at ML.)