So as you can see the entire inside of the cab is structured with wood. One of the main reasons you dont see very many 30's chevy pickups and cars. So our first step was to replace all the wood with sheetmetal and replace all the rust also. Here the start of the left and right side of the floor structure.
We built it out of 16G cold roll sheet. Bent an angle then caped it and stiched in angels top and bottom to add strenght.

The drivers side tacked into place.

The back edge of the cab corner

Front edge tacked to stock floor

Here's both sides tacked into place.