Got to the back field today with a cordless drill, sawzall, and as many batteries as I could find... And chopped the donor extended cab into two pieces. Went surprisingly easy, separating it at the seam in the front floor foot well. I cut thru the inner and outer rocker panels in line with that, and cut the roof just behind the windshield.
Hauled it up to the barn with the tractor, and wiggled it into the increasingly crowded barn. Did some measuring off the crew cab, and my other extended cab, to establish a base line for measurements to figure out exactly where it will get cut.
Because I have cut the floor, rocker panels, and roof much longer than needed, it will be trimmed back to fit. I started that by removing the outter rocker panels. To do so, I rolled the cab section onto its back wall, making it easier to work on, as well as give me a chance to get a good look at the amount of rust damage that will need dealt with... more than I had hoped, but since I only have $100 in the white cab anyway, I'm not gonna complain... too much.