I thought I would shoot a couple rolls with my Super Nettel I which was a mistake, perhaps. The camera is in excellent condition and the shutter had been working very well. To access and clean the inner lens, I cocked the shutter, set it on B, and opened the shutter. After light cleaning of the lens, the shutter closed as expected but from that point on it would no longer operate. The advance continues to turn but the shutter no longer sets. I hate to tackle the repair on these old Contax I-type shutters. I replaced the ribbons once on my Contax I but this doesn't seem to be a ribbon problem. Any suggestions? Perhaps a good repair shop in Europe? Thanks for any help.