Compur serial number starting with A (and how to open)?

[diluted dilated]

I recently acquired a batch of lenses, and among them was one that came in a Compur shutter that I have been unable to date, as the serial number starts with an A (pictured). The number alone would make it a late 1910s model, which of course it isn't. Can someone give me an idea when this was made? (The lens that came with it appears to be from 1938/1939.)

146005

While the fast shutter speeds on this one run very smoothly, anything slower than 1/25 takes several seconds to release. As such I would like to clean and lubricate the shutter, but the instructions I can find online seem to be for different models. On the front it only has a tiny spanner-head screw (in the left of the picture, next to the lens thread), while in the back there are 3 regular slot screws. Should I begin with those 3 screws?

Thanks!

[Louis Pacilla]

Take a look at this link. Repair manual for Compound/Compur shutters in all varying types including the type your asking about. Make sure you browse the entire catalog but I think your looking for the info in chapter 4.

http://benoit.suaudeau.perso.neuf.fr/manuels_rep/obturateurs/compur-repair/01-03.html

[diluted dilated]

Thank you Louis! Mine appears to be an older version of the Synchro-Compur 1-MX (http://benoit.suaudeau.perso.neuf.fr/manuels_rep/obturateurs/compur-repair/04-42.html). This repair manual (http://benoit.suaudeau.perso.neuf.fr/manuels_rep/obturateurs/compur_rapid_shutter_repair(2).pdf) (for another model) in the same directory has instructions on how to remove the face plate.