For the battery problem
Originally Posted by asteroid_death
- you can try and locate the hearing aid battery better with a ring of plastic...
- or remove the base plate and solder in a Shockley diode to reduce a silver cells 1.5V to close to the 1.3V of the Mercury cell the meter was calibrated for, the silver cells hold their voltage sensibly constant like mercury cells used to.
- buy an ready made adapter incorporating a diode to allow a silver cell to be used.
The OM1 used a copy of the Leica fabric shutter most of the good repair people can repair them.