Shafovaloff1
Well-known
Try using a nonstandard flash that sends a jolt through the system. Also, shine a flashlight on the meter sensor on the bottom below the shutter curtain when you take the lens off. I would like to find a copy of the repair manual. If I ever find one I will post it where everyone can see it. Though it is a somewhat delicate operation to remove the camera top it is not more difficult than a Leotax or Nicca. The bottom is easily accessed but watch out not to undo any solders and note the position of parts. Dismantle in a tray or something. I have posted pictures on PhotonMe Flkr. And can send files which have access to shadows if anyone is interested.
Shafovaloff1
Well-known
I would not use contact cleaner for fear that it will mess up the mirror surface for the rangefinder prism located very close to the speed changing dial. Try the powerful flash out and or shine a bright light on the sensor under the curtain.