So as I continue to wait for my CSX 289 roller to show up (26 months and counting) I finally tackled the original dash clock. I had purchased last year two inoperable clocks (Cobra: CE.2194/08 - top adjust) and (Sunbeam CE 3131/OO - bottom adjust). I was able to salvage parts from both clocks to create one correct and functioning Cobra version.
In that process I installed an optical sensor for the balance wheel from a kit supplied by Clocks4classics.com. The excellent instructions provided by them allowed me to delve into the intricacies of these clocks successfully. I had no prior experience in watchmaking or repair.
I now have an original and functioning 289 Smiths clock for my car when it finally arrives.
For the record, the clock draws ~6.5 milliamps.