72 GMC Sierra Purchase - Thoughts?

[mgm60]

I'm looking at buying this 72 GMC Sierra. SPID is on the truck and seems correct for Sierra Grande (YE9). Its a BB now but was originally a 350. Looks like it will need rockers, cab corners and work on the lower door skins at some point and I can't tell if this a a repaint or the original paint, or a combo. In one of the pictures you can see the primer is black on the roof and the firewall is also black. Thought the cab on these was primered in red so not sure what's up with that. Don't know if these wheels are correct either. Going to take a look at it and wanted to see if folks on the forum with more of an expert eye could provide any opinions on it or suggestions on other things to look for.