I have a Konica 80-200mm 3,5 zoom lens with very slow open-close diaphragm, for as far as I can see there is no oil on the blades, I just hear a spring inside struggling to activate the blades movement.
If it's any help I have some schematics for the 80-200mm F4, both one-touch and two-touch versions. These are more recent than the F3.5 so there may be considerable differences.
