I took the panel apart today. I can finally confirm the clock is powered by a battery. A GP 186. It's a little work getting to it but it can be changed. There are two type of bulbs, two clear winker bulbs and two larger bulbs with black looking caps which produce the amber illumination for the panel.
The rear of the panel with all bulbs removed.
After removing 4 screws you can access the instruments.
The left panel lifts off.
Remove two screws on the rear and the speedometer comes off.
The metal wheel spins(from it's connection to the cable) and moves the needle.
It's hard to see but the gas gauge is run off a bundle of copper wire.
The clock is glued in and wires run to a battery holder screwed into the panel. The wires connect to the battery holder via solder points and a cap of hot glue adds reinforcement (I had already broken the cap off in error here. Be careful to leave it attached)
The battery holder is attached to the holder with two screws. A twist of a Philips head screwdriver opens the holder.
Battery
Bulb for illumination
Winker bulb (on left)
I had tried to change the bulbs in the original panel and had a hard time removing the rubber housing from the panel, concerned I would break something. I now think the wires and connection are tough and the rubber housing is to be removed from the panel by pulling on the wires.
Resemble everything in the reverse order.