To answer a question about the decking on Southern Greenville Steel Car bulkhead flats, here is the title block half of GSC drawing 36028 but I do not see any references to the planks being wood or steel. The photo of Southern 116184, I took at Atlanta July 2001 shows their wood decks clearly.

The early Intermountain (?) center beam flat may provide a starting point for one of the bulkhead versions. The tie down ratchets on the kit are very nice and starting with an underframe and deck would save a lot of scratchbuilding. I have lost track of which Southern car had the same truck centers although that length could be modified rather easily.

Ike