Sounds like the PO took good care of it.

With its age it would be a good idea to have the radiator serviced, should run under a $70 there in Sac. I had mine done a few years back and with the header rebuilt it ran $96.

More than tread lightly. Leave it like you were never there, nor anyone else.
'90 X-cab 4.88's 33 BFG AT's, rr ARB, Headers, Ignition upgrade, cold air induction.
'91 X-cab 5.29's 315's BFG MT's, rr ARB, custom bumper and flatbed