The wood in this car was all original and in place but it was badly split and dry rotted in critical areas. Here are some pics of the steps I took to replace the wood. The front edge of the door was stamped 1/8 steel, so I left it there and added to it. The top edge had a mild radius vertically and horizontally, so I used an E'wood shrinker/stretcher to make the sheetmetal bends. These cars were wood structure with sheetmetal skin tacked on, so my first step was to weld the edges to the table so the skin would not move while the skeleton was replaced. The rest was just bending 1 inch square 16 guage and 14 guage tubing to match the radius. The door weighed about the same after it was done, but had zero flex. 1st pic is from Sal's wood of a 5 window to show the extent of what needs to be done on these early Chevys.
I have spent the last two days doing this myself. Doors rotted 6 inches up, it had been in an accident before it was tossed in a feild and abused for god knows how long. The door jambs and striker plates were scrap, I had to start with just rotted out sheet metal. give me another month and I might have something that resembles a 30 3 window.
Whew, thank God my Dad's 31 wasn't that bad. He was able to repair what little rot he had without too much trouble.