A/C - Sticking with R12 but looking for help

[gable74]

I'm not an A/C guy but I know enough to be annoying. So I have a few questions and looking for some advice. I have spent a few hours reading old posts and questions on the subject which led me to more questions . Anyway here are a few I could use help with.

First, I am pretty sure everything as far as the A/C setup on my truck is factory original. The guy I bought it from said the A/C just blew warm air but since he had the truck in Upper Michigan he never really had a need for it anyway so he did not attempt any repairs. One of the first issues I noticed was the dry rotted vacuum hoses which I fixed so the passenger door flap as well as the heater valve were all working correctly. Just this small fix actually showed an improvement in temps of the A/C, but still not near where it should be.

Now what I would like to do is tune up the system. From what I gathered from other posts it would be something like this:

Replace O-Rings
Replace dryer
POA adjustment
Schrader valve replacement/adjustment
overall cleaning of parts and contacts
evacuate the system
test for leaks during vacuum
check/replace oil
charge with freon
Considering replacing the C6 compressor with an aluminum one

What I would like some help with are specifics of each of these steps and any I may have left out. For example, I do not know where all the O-Rings are or whats involved in the POA and schrader valve repairs.

I don't want to turn this into an r12 vs r134 debate. I have access to enough r12 to justify this path for now.

Any help would be great.

Thanks,
Jimmie