He got Lionel to run their extrusion for him - or got Lionel's supplier to do it. His mistake was in not using the baggage car extrusion, which was pretty darn close to a Budd car. The ones he did run have a letterboard on the lower half, and as far as I can tell, there is no known prototype for that.
the extrusions were done with 2- rail in mind, so floors, couplers, etc. were up to the kit builder. A table saw and some clear pine makes very good floors, keyed to the inner shelves of the extrusion.
He did supply the Lionel plastic ends, which fit perfectly and looked good.
Since this is the 3- rail forum, let me recommend K-Line Budd cars - they came in various lengths, and were much more accurate models.
For Santa Fe modelers, Budd baggage and postal cars came as short as 66', which is awfully close to 15" in O Scale.
