New Member w/72 K5 blazer

[72K5CSTDarkOlive]

Newbie here but not new to owning Blazers (10+ years now) Can't believe it took me this long to find this great forum.

I have 72 Blazer that been sitting for the last 3 years and I'm saving up enough money by spring time to start the restoration process. Here's a little background on my K5.

Purchased back in 03 from the 2nd owner in Santa Cruz, CA. However, he only had it for a couple years in his hands. The original owner purchased this in Hollywood, California back in 1972 and it lived most of its life in Hollywood, Sunland, and Salinas, California. It did spend a few years in Pagosa Springs, CO. I was able to trace all of this bc the original owner kept all of his registration papers.

The PO owner did a really nice job restoring the interior back to original. He claims it has the original paint except for the rear side panel which was involved in an accident back in the late 70's..

After reading through a lot of the Blazer projects and builds threads, it has inspired me to do a full frame of restore. I know most blazer have some sort of cancer and I started to look around mine to see if I have any.

Questions
1.) What is the best way to determine if it really is still the original paint?
2.) Is the right rear side panel usable or am I better off replacing it (see pictures)?
3.) The floor boards look good to me, but I'm no expert, I noticed there is some some coating used in various spots. Looks like some kind of rust preventive material for possible surface rust that starting showing up. I'm curious to hear what any of you guys think?

Pictures to follow very soon.. Hopefully I can get them right the first time..

Thanks,
Mike