[HO455]

[/QUOTE]Regarding the drip rail. The drip rail has seam sealer in the bottom of it from the factory. The blue truck appears to have been repainted and the paint appears to have been applied over fracked seam sealer. You'd have to remove all that to truly gauge the condition underneath.[/QUOTE]

That drip rail sealant is bad and the problem with that kind of failure is water runs through the seam between the roof and the door frame and then down inside the A pillar into the rocker area. The A pillar is a more difficult area to repair than just a door sill and is hard to stop when it has begun to rust in earnest. This link will show you a rusty truck at what most people feel feel is the upper limit of repair for a high value truck. If it was a 70 Dodge Daytona you wouldn't think twice about this much work.

http://67-72chevytrucks.com/vboard/s...d.php?t=705214

If your goal is more toward driving the truck as opposed to the joy of rescuing a truck, then the less rust the better. This will put you on the road sooner. If your drawn toward the work involved with saving a truck then door sills and rocker panels are not deal breakers as long as you don't count your own labor into the cost of repair. These are fairly easy to replace on these trucks and there is lots of information on how to do it. The tools necessary are not out of the budget for most folks if you do your home work and shop for used tools.
You however can never get the cost of major rust repair back on these trucks. Don't forget to take your pesonal situation into account. Do you have the patience for this kind of work? Can you live with your mistakes? Is your family tolerate of the time that these kind of projects take? Do you have a place to work on the truck? These questions may provide you with the answer your looking for.

Having lived in Nevada in a previous life I know that you can find trucks sitting around if you get off the beaten path out of the cities. I found my 52 in Ely by walking in to a gas station on the edge of town and asking the owner if he knew where I could buy an old truck. Six hours later I had a $300 truck on the tow bar behind my 64 Galaxie and was headed home. There ended up being two thumb sized rust holes in the whole truck. Just getting the truck was an adventure in itself.
Good luck in your search and let us know how you do.