I have a Sigma 75-200 Zoom built about 1982. The focus mechanics are on the wrong side of the barrel compared to the mating scale, and the iris is working backward. The surplus shop where I found the lens has several in the same condition. Glass is in excellent condition. I have worked on several lenses but do not have a good clue on how this one disassembles. Does anyone have any information on disassembly?
Follow-up: Since first posting I disassembled the lens and found that the iris had been modified in a most unsatisfactory manner. The key to disassembly was hidden under the rubber focus gripper which can be 'rolled' forward and off the lens to expose the many access screws. The iris had been reassembled backwards. I give credit to the person for leaving the screws clean and showing no evidence of abuse. Now, due to missing iris blades this zoom is headed for a serious modification to insert another iris assembly. Thank you. Jaye
