Chris, I have a Chevs of the 40s catalog. On page 173, there is an exploded drawing listing the 40-46 cab body parts. This may help. The only cab part they list for sale however is the floorboard that goes from door to door. This is fiberglass, not metal. You can get a catalog at
www.chevsofthe40s.com. At least with this, it may give you an idea of some of the parts you may need. I have found some parts in wrecking yards and ebay and other bolters. Barry Weeks has been a great source of parts for me. He is on the Stovebolt Page.