1972 CdV, more questions

[Roger Zimmermann]

Hopefully I'm not alone with that situation: there is a new toy, and there are multiple issues!
The new ones: at home, when I put 12V at the clock, it began to tic-tac (I have to check if I have 12V in the car at the connector). Fine! I removed the electric part just to discover that the contact is almost entirely eaten: the shiny part is all what is remaining; the rest is copper and may stick to the other contact. How to repair that?
Other issue: I removed all the parts constituting the speedometer. There was traces of old grease on the plastic gears. Must those gears be lubed, and if yes, with what? I read that it can be done white lithium grease; vaseline may also be an alternative.
Due to some issue with the radio, I opened it. I cannot do anything, I'm not equipped to check radios. However, I saw that the belts for the cassette player are...probably 47 years old and may not survive a long time. Are they available?

[fishnjim]

gears - yes, small amount of lube - white lithium grease.   These early plastics are not as good as the newer ones in terms of wear.   Glass filled nylon came much later.   Option - replace with a newer gear of same size, if worn.   
No specific thoughts on the clock.   If you can't replace, then maybe can find someone who works on them that might have some parts.   A lot of things can be repaired, if you can get the parts, but components like this were not readily available for everything when the labor cost of repair exceeded the cost of replace.  Another option is to replace the clock works with something else, non-original.