Repair MAMIYA SEKOR 90mm 1:3.8 for RZ67 motion lapse film

Repaire MAMIYA SEKOR 90mm 1:3.8 for the Mamiya RZ67 / RB67. This lens has this problem that the mecanism at the back of the lens was a bit sticky, so it dosn't work correct. When assemble the lens again take care of the brass ring, and the 2 nochtes on each side of the shutter, that connect to 2 pin's at the bottom of the housing.