You have an interesting and nice quality “tandem wind” movement there. The idea behind the design was to allow the disassembly of either the strike or time without having to disassemble the entire movement. The two assemblies are linked together by means of a coupler or sleeve (not sure of the correct terminology) on the winding arbor. I have either a pdf of or the actual link to the original patent (can’t remember which) somewhere on my laptop or on an external drive. I’ll try to dig it up and post it for you up here today. I’m not at all sure of what may be causing the locking up of the arbor. It could just be gunked up with old dirt and oil. Pulling it apart to see what’s going on would probably reveal the problem. I’ll try to find the info in a minute and we’ll see if that helps.