If you are close to NH you should try VSR ( Vintage Sports and Racing) in Bow, NH.
They owner Mario is one of the best BMW specialist in New England and he is very honest, polite and treat you like a friend. I got my Ti from him.
You can visit the website
www.vsr1.com and take a look.
But if any of you knows a good shop in or around Fairfield, CT pelase let me know.