[rotorwrench]

The Briggs and Murray bodies were different enough that they had a fair amount of differences in the wood structure that held them together. Both companies manufactured bodies for other automobile brands and they used wood for them as well. In Charles Sorensen's book about his time at FMC, he made mention that Henry had questioned the price that one of the subcontractors was charging FMC for the steel they were using in body fabrication. This led to FMC's rolling mills supplying them with the steel they needed after that point. He never mentioned anything about wood though.

The Henry Ford site has a lot of info available. The Iron Mountain facility was where all the station wagon bodies were made after it came on line. Ford likely made all the wood used in the bodies produced by FMC there but most of that was for the top structures and the interior trim fitting plus the floor boards & seat bottoms/backs at least with respect to the model A. A lot of Model T bodies were made there during that era.

Henry and Clara Ford were close to Minnie Kingsford who was a first cousin. Henry had her husband Edward scout the properties and site for the Iron Mountain plant where the hard wood resources came from.