Good advice on the "who" does the CLA. I had my 3.5 F CLA'ed about 5 years ago by Bill Maxwell (Maxwell Precision Products) in the Atlanta area. Bill also has a line of replacement focusing screens that you might want to upgrade to at the same time. I didn't have a focus issue like you are having but I recall Bill verified the taking lens focus with the viewing lens as part of his service package. Bill and Harry Fleenor (did I spell that correctly) on the W Coast are apparently buddies, if that says anything professionally.
Originally Posted by rich815