I'll mention another shop, D & M Restoration in Greenville, South Carolina. They specialize in gauges and clocks for classic vehicles.
Now, that being said, I'll mention another -- Instrument Services Inc in Roscoe, Illinois. Borg made your clock originally; Borg has since been purchased by what has become ISI. They can rebuild/repair your clock to original, and they also make movements to update your clock to modern quartz movement. These movements are used in certain new cars, and is an excellent product. I have a conversion in my 64, and has been running perfect for several years. You can buy the movement if you wish, and convert it yourself.
The people at ISI are wonderful, but it may take awhile if you send it in -- they have quite a backlog. D & M can take care of you (using the same movements) much faster. Original or quartz -- your choice.
I was doing clock conversions for a time, but decided to stick with only radios instead. However I can tell you firsthand the ISI products are great.