Yep, I'm definitely going to fill the side windows in. I've already removed the window from the right side, squared it off to make it easier to cut the patch piece of sheet metal, and have recorded the exact dimensions.
The truck was too good of a deal to pass up, even if the windows were in the sides of the panel. I figured I could weld them up--and I can. I just have to be careful with any excess heat as I weld. I want to keep any warpage to a minimum.
Rockettruck