Hi Chet, I have a 1929 Plymouth (4 door sedan) model U that I'm in the process of a frame off restoration. I've been working on this project for 10 years. I'm recently retired so I will now devote time to completion. I took a few pics of the piece you requested. It is made of aluminum (painted black) and has holes for nails every few inches. Let me know if you need more info.
Regards,
Robert