How do I remove the OM-1 ASA dial?

Question:

How do I remove the film speed setting dial from the top plate of an OM-1? I've looked and looked and just cannot see how it is retained.

The bezel for the ASA knob is attached to the top cover -- it doesn't come off (or shouldn't!). The easiest method is to swap tops entirely.

There are several versions of the knob itself, and while all are similar in construction the parts aren't compatible -- in other words, you'll have to replace parts from one knob with parts that are of an identical type.

In short, the knurled outer part of the knob unscrews from the inner part, which is inserted from underneath the top. Be careful trying to unscrew it, though -- the earliest models had set screws, later types were glued, and the latest versions of the inner part are plastic and the "teeth" for the ASA latch will shear off easily.

The plate with the ASA #'s just sticks onto the top of the knob, but on some versions there is a separate plate on the top (which is no longer available), while on others the top of the knob is part of the insert itself and not removable separately. In both cases, some are plastic, some are metal -- be careful!