Nice project, Scott. What will you use for the car ends?
Also, any chance you can photograph the car ends straight on and pair it with a photo of other extruded aluminum shells for comparison? A side by side photo would be optimal showing the interior of the extrusions.
Carl, I have been using traditional Lionel car ends that fit ok although not the ultimate choice. I would like to swap these out later. The sheet metal ends OK sends are useless. Here is a pic of the phase III Slumbercoaches from OK with the Lionel ends. The car to the left is a Lionel 21" car, an former CSX repainted in Amtrak phase III.
Here are comparison pics with a K-Line aluminum 21" dining car with phase IV paint by Christine.