In addition to Soundsmith you could check with www.phonocartridgeretipping.com. I have had Andy at Phono Cartridge Retipping and Soundsmith both perform work before and have been happy with their work.
There is a company in Europe called Expert Stylus (I think) that does this also. No experience with Expert stylus, but I have read good reviews.
There is a company in Europe called Expert Stylus (I think) that does this also. No experience with Expert stylus, but I have read good reviews.