Found a truck

[Yamaha74]

I found a 68 Chevy longbed yesterday that is for sale. This truck is a 1/2 ton, 2wd with a 307 motor and 350 turbo trans. Stainless steel dual exaust. Motor is pretty fresh. I haven't drove it yet but I heard it run yesterday. The body is in alright shape. The rockers and cab corners need replaced, which he already has but hadn't had time to put them on. Everything seems to work on it from the lights to the guages including a aftermarket tach. He is wanting $1,800 for it. I know I have seen some posting on this site about the window frames being rusted out and if that is the case they are pretty much unrepairable. I don't know how to tell. They don't look that bad, but I am in no way an expert. If I can get some pictures would you guys be able to tell?