Questions on Preserving Cab Interior_1977 GMC

[AbigailAmelia]

I'm excited that my new-to-me 1977 GMC Sierra Classic seems to have a pretty nice interior (original?), and I'm looking for input on how to preserve it, what products are safe to use, and what products/chemicals to avoid.

Lots o' questions here that match up with the photos. Maybe you have an answer to one or two?

1) What can I use to clean/preserve the interior door panel?
2) The headliner is intact, but it has The Little Tear That Could. What's the correct way to stop this tear from expanding?
3) The door panel is chipped. Until I find an original replacement, is there a safe way to trim the chip to make it look less ragged?
4) The shifter knob likes to almost slide off.
a. Any tricks to keep it in place?
b. Any cool sources for replacement knobs in case I stray from original?
5) Certainly the dome light originally had a cover? Does anyone have the source and part number for the original cover and bulb?

Thanks!

Michelle