Update..... the seller did email a pic of the original build sheet, but the resolution wasn't good so I couldn't zoom in and read the small print. I could tell that the original sale price on that truck was slightly over $40k though. Take it for what it's worth.
I also found out more about the discoloration on the frame rail. The truth came out.... he moved down here from Michigan last November. I know what you are thinking already, lots of road salt. Well, it wasn't up there for a full michigan winter but maybe it only takes a little to start the rust process? I wouldn't know that living here in SC. Also, the seller works for Pulte Group builders and drives in a lot of new neighborhoods under construction. Sometimes in heavy rains the streets will get covered with mud and he may drive through some of it. So, that's why the frame looks looks like it does.
After learning that, I declined to go look at the truck. I told him I appreciated his honesty, he's a real nice guy but that truck wasn't for me and I will keep looking some more. Btw, I just don't see any of these "new" 4x4 2013 trucks you guys keep talking about for this same price, or just over $30k anyway. But, I really don't want a brand new truck. Too much depreciation that first year, which is why I am trying to find one that's no more than a year or two old. Thanks for all your comments though!