This is my first post and I hit enter before I wrote the full explanation. Thanks for your patience.
I have replaced all the mainsprings, installed new balance wheel and bushed worn pivot holes. Time, chime and strike are all running well. It is the calendar mechanism that I can't figure out. It changes every month on the 27th day instead of the prescribed 28th for February, 30th for April, June, Sept. & Nov. and 31st for June, March, May, July, August, October & December.
The instructions say it only should need manual adjustment of the hands for leap year.
The hands on the calendar face are riveted so I have not been able to pull the calendar mechanism out of the case.
I have not been able to find any drawings or explanation of how the mechanism is designed and should work.
If anyone has info of how to proceed, I would greatly appreciate it. Thanks.