I recently acquired a 105mm f/4.5 Carl Zeiss (Jena) Tessar in a rim-set Compur (1-250, T & B) shutter (no flash sync). From the markings on the lens and shutter and the style of lettering, I think it was probably made in the 1930s. I'd like to use it on my Crown Graphic as a normal lens with a 2X3 roll back but the shutter is a bit slow, especially at the slower speeds. Can anyone provide guidance on how to dissemble the shutter enough to just clean and re-lub it? It looks like you can separate the back of the shutter (with iris) to expose the gear train by removing 3 screws on the back.