Hi Will,
You did ask for 'any help ...'
I found this
http://daniel.mitchell.name/cameras/copalmxv/copalmxv.html
I have found that for similar mechanisms, that over time the oil deteriorates, and gums up the works. It used to be easy to degrease similar devices by suspending the mech. over a small container of carbon-tetra-chloride, (inside another larger container) for a period of a few days, the fumes 'dissolved' the grease. You probably have to use safer chemicals today, but they are possibly not so effective. If you know of a local mechanical watchmaker, he may be able to advise, and supply a few drops of a suitable light oil. To apply the oil to pivots, then a sharpened wooden matchstick is ideal, you can get the right sized drop on the point, then deftly transfer it to the pivot. If all else fails, then wd40 may suffice as a lubricant - not sprayed on of course.
If everything in the mechanism is metallic, then immersion in an ultrasonic cleaner may be a good option for degreasing - even the domestic dishwasher, (but make sure it's rinsed and well dried ;-).- before re oiling.
Best wishes,
Ray