I've had a bunch of F2's CLA'd by Essex Camera in Carlstadt, NJ and they are reliable and efficient. But it's been a while since I've used them and their web site doesn't seem to be working (http://www.essexcamera.com/). Here's their contact address & phone info:

Essex Camera Service, 100 Amor Ave., Carlstadt, NJ 07072. Phone: (201)-933-7272

Though I've never used him, Ken Ruth of Photography on Bald Mountain has a very good reputation on working on old-school cameras. His web site is:

http://www.baldmtn.com/

-Kevin