Even if you cannot get the RF to couple, you can use scale focus. These cameras were better than most ever thought. These lenses are utterly superb.
What I would do: First, I would remove both the front and rear element sets. (This also gives you the opportunity to really get the inside of the glass immaculate.) Then I would carefully (and sparingly) drip a bit of lighter fluid onto where I thought the focusing helical was (outside the main body of the lens and aperture, of course). Once that helical gets wet (and hopefully ONLY that and not the aperture blades or shutter blades) you can begin working it back and forth with the focus. NOTE: if you do get some fluid on those blades it is not the actual fluid that is bad because it can be dried off with a hair dryer, but the fluid mixed with the helical lubricant that you are trying to remove can cause a sticky aperture or shutter once the fluid dries and the oil remains.)
Of course, it would be better to be able to remove the lens helical completely but that is tough, even for one experienced somewhat such as myself. Ideally, what you want to do is wet the helical with the fluid and then somehow draw that dirty liquid off and do it all without invading much else. I say to remove the lens elements so that any fluid that gets caught inside can much more easily be removed. Of course, don't get ALL the lubricant off: leave a bit on so that there is not grinding on the brass.
At least I have provided a theoretical paradigm here but, of course, practice might prove harder.
The top of the body is where the focus adjustment should be: usually a couple of screws that control the horizontal and vertical matching (ghost) image that you see in the RF. At this point I cannot give specific info for this particular camera even though I am certain I must have worked on it at one time. - David Lyga
