As on my former 1960 Coupe deville the original clock gave up after a short while when getting it running again after several years standstill. It was a complete melt down of the solenoid coil winding up the clock. I then decided to change/upgrade to a modern quartz clock mechanism getting rid of the old mechanical clock. I did this several years ago on my 1960 Cadillac (see Link)
See pictures below for the process of upgrading to a modern quartz mechanism which I bought at alocal hobby store (Clas Ohlson) for about 15USD complete with arms and mechanism.
I have to tailor made change the supplied clock arms to look like the original ones and I think I got it quite ok. If you have any questions regarding this pls email me….