Here's one I hadn't thought of!
I do not endorse this solution.

someone soldered a bushing to the inside of the plate to fit the short arbor. I do not know if the pivot had broken or wheather this is a replacement gear.

the gear/arbor/pivot

I've had two cuckoos come in last week. Started them today. Photos above were part of the first one. The second one is shown below. This is the center arbor of a "one-day" Regula. You should see the guy's forehead!

Thanks for sharing that one. I had not seen that one before. I guess he thought he could solder and cut a pivot on the end of the arbor better than he could re-pivot. Sad.

I just did a JC Brown steeple that had popped a strike spring out. The cause was that the center rail of the rear plate was sprung back to make up for a botched repair. The rear escape pivot had a section from another plate cut out and soldered on to 'create' a new pivot hole. Very fortunately even though the spring let go, it was able to spread the plates rather than break or bend the 2nd strike wheel. The hammer arbor was also loose in the case.

After lots of flattening of the plate, pivot polishing and a rebush of three holes, it's once again running. Just delivered it today.

The customer had to pay more to fix something already 'fixed'. But at least she's happy now.

What some people will do to avoid paying a pro.