My Bessa R 35mm body needs its rangefinder adjusted for vertical alignment. It's easy to remove the hot shoe base to get access to the adjustment screws through access holes. But the very small slotted vertical adjustment screw is secured with a yellow, waxy thread lock material. Perhaps this is common, but in searching here and elsewhere I haven't found tips for removing this stuff. I've tried household acetone and not had much success. Any suggestions?
I suggest not using acetone anywhere near cameras. That said, the thread lock doesn't normally completely stop the screw from being turned. It's there to stop the screw moving due to vibration etc. The waxy type of lock can normally be scraped off. The harder stuff will usually crack when the screw is turned.
Acetone should generally be considered unsafe as even fumes may permanently fog acrylic - which is present in just about every camera made in or after WWII.