Another example of the arrogant attitude that exists in the Swiss watch industry. I see no reason why the dial side of the movement can`t be stripped to correct the fault, the rest of the movement could be left alone and the cost of repair could be minimised. Given the age of the watch there's a strong case for having it fixed on a goodwill basis unless it can clearly be demonstrated that the owner's caused the problem (unlikely).
I fail to see why a watch at this age needs fully servicing, it doesn`t and they know that. Arrogance, typical Swiss.
Paul