I'd guess the best way to know if the truck you're looking at is "all there" would be to have a copy of the service manual in hand.

A google image search my provide a number of cameo images to use as a general guide as to what to look for, but i'd guess your best resource would be the free GM Resto Pack for the Cameo, and/or the GM Service Manual for one.

an idea is only stupid if you think about it rationally.