What you have circled in the picture is the crown wheel and screw. The screw should have a shoulder section to keep it distanced, or a (lost) washer was used there.
That is why I wash with petroleum only and IPA only, by hand. And mild ammonia only if there are brass / gilted parts.
Then every other thread we read about beginners (but not only) getting fixated on on machines and commercial solutions.
Unfortunately not, i was thinking of that, but the ratchet wheel has a recess so the screw could center it and the wheel should be able to turn around it. Now that I see the picture it is actually upside down but it is just because i put it back for the picture and did not pay attention.
I got a puw 60 what I cleaned and would not run because the left handed ratchet wheel screw is pushing down the ratchet wheel and locks it. As it cannot move the movement would not run. This is how I received it, originally i thought that it is just dirty so I cleaned it. (interestingly the ultrasonic bath removed the nickel/chrome -never could make the difference- plating at many places) What am I missing here? A washer? Or something else?