62 series prices are all over the map. Seems as though all the good points of the low mileage are pretty well cancelled by the condition of the body and paint. Since I've no need for a project, probably 2500 tops to me.
Well, the fact of the head gasket failures are well documented. You can buy one any time "needs motor work" for 1000 bucks or less. Stay away unless you're either going to do the repair, have it done, or can prove it's been done.
You probably should have someone torque the motor under load while you watch. I suspect you'll see movement, indicating a broken motor mount. Either that, or your water pump is going.
I had a great experience with ccot's best weatherstrip. The mold is identical to factory, every curve, notch, and divot is identical. Outside of that, it's slightly thicker. Worked great for me, and believe me, I'd tell you if it sucked. You may have to adjust your strikers a little looser...