89 200 questions + Boost Gauge Install

[Samir Shah <gofast1@home.com>]

I'm working on electronic gremlins this weekend - got a bottle of
Stabilant - and am also installing a stereo/CD changer. 

Questions:
1) The stock stereo is 12V continuos power. Did the factory provide
switched power, and also power from the dimmer? Where can I tap into
these?
2) Anyone want a working Gamma radio in decent condition? BO gets it.
3) Is there a circuit breaker for the passenger seat? Where do I find
it? (listed in bentleys, but no sign anywhere so far).
4) I have a VDO boost gauge I'd like to install while I'm at it. I have
not yet figured out the boost plumbing - anyone have a
install-for-dummies guide?

Thanks in advance. Samir.