Depending on what service you need, I recommend the folks at Quinlan & Fabish. If you need routine cleaning, dent removal, etc., then they do a great job. They are the preferred school music dealer...
Steve Lewis has not done repair work for many years and is no longer at the Chicago address. His horn building operation is now in western Evanston. For top quality repair work, Ron Pinc has been the choice for some time, but his availability is limited. You'll have to make an appointment and wait. Try contacting him through The Laskey Company 5401 Patton Dr. Suite 116 Lisle, IL 60532 *(630) 889-2188* If he is unavailable, he should be able to give you some recommendations. Richard Hirsh