I like the thorough collection of pix!
They certainly clearly show the issues.
Does look like your valve cover is leaking up front (the old dust-filled sludge), but the oil spill's way to wet by the fuel pump to not be leaking.
Interior actually looks reasonable, the rear seat at least seems good.
Dump the K&N air intake, it's not a good enough filter, and it's sucking in hot engine compartment air. Swap back to the Mitsu air supply system from the passenger fender, and get back to cool air intake. Get the REAL Mitsu air filter in the carb's pan/housing, it's the toughest filter out there, and will help a LOT on future wear. If there is no filter around the carb, you're in deep sh!t, as the warm air intake for cold starts is after the K&N (it's the short fat air hose coming down from the pan's "handle".
Lots of small lamp/lenses needed, but they should be easily found among the guys already offering help.
My vote on the sheet metal is to replace it if you're gonna re-paint...

I'd like to contribute a "spare" (If I still have it...) rad from my pre-4.3L days with the 2.6L , it's an aftermarket nearly new one I scrounged at a wrecker's as a spare. I no longer need it. You cover the shipping, and it's yours. Might take some excellent packaging to ship from BC, but should be good.

Colorado is one of my favourites. Been there 3 times now, and met the Capn while there the last time, and HighMtn the past 2 trips, and they're for real. You're certainly meeting the right guys here! ...I've been a regular Russell-partstentman.com supporter, too, he's got the stuff!


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Oh, and get the Stant 180 thermostat.
Thermostat: Stant Heavy Duty 180 degree, part # 45868

For some reason the KYB's seem the best match for this rig.
KYB Gas-A-Just front shocks, KG5603A
Rear KG4034