Question on locations

Well I got to the point on my restoration where I began to do the engine bay wiring. I got it all hooked up except for 2 things.

1) Where is the low oil pressure switch? Is it on the instrument panel? What does it look like?

2) Where is the temp gauge sending unit? the temp gauge on the instrument panel?

3) neutral saftey switch? back up lamp switch?

4) Is there a positive or negative side to the ignition ballast resistor? or is that determined with where I plug in the cables that go to the resistor?