My understanding is that there are many repairpersons who are able to work on medium format folders, particularly their leaf shutters. Mr. Kreckel has a mixed reputation--I've personally had a positive experience w/him, but others have not & have criticized his work on the Rangefinder Forum. I think everyone agrees that Mr. Ruth is excellent (he's repaired/serviced several folders, among other cameras, for me) but he can often be backlogged, which can be a problem if you're in a hurry. Essex Camera Service in NJ has a good reputation & Frank Marshman in VA (trading as Camera Wiz) has been recommended to me in the past.