Just got a lens back from Sherry. She's worked on a number of them for me. I've never sent her a camera, but when I need to send out one of my M's, it will be to Sherry.
There's a guy in Seatle who's very good with the older RF's - worked on my Minolta 35 Model II. Can't remember his name at the moment and I'm out of the country... If you're interested, I can get it from a friend.