Soooooo, I got everything working on that F-1n except for that sticky needle. I really did not want to take the mirror box out to get at the mechanism as I tried it on my test subject and it is not an easy thing to remove and especially replace.
I figured if I washed out the area it will eventually run free … but every time the Naptha dried out the needle would stick. I figured that it needed some oil to keep the metal parts moving … but that means opening it up !!!
Then I remembered a tip that someone told me … put a drop or two of Nyoil in a bath of Naptha. Well I did not have any Nyoil, but I did have some Moebius 8040 watch oil, so I made a bath … then dribbled some into the opening for the diaphragm sensing lever (or the servo port if it isn’t covered).
Some exercise of the lever and stop down switch … and then waited for the solution to dry.
Next day … the lever does not stick !! Thanks Dimitri.