Ran into this in my wanderings, remembered your question. Not sure if its what you needed.

http://www.goodmarkindustries.com

Cab Rear Panels
4141-490-551 1955-59 Pickup (without large rear window)
4141-490-552 1955-59 Pickup (with large rear window)

She's one 55 year old with a spare tire that looks good!
It's not rocket surgery. . . .


http://www.picturetrail.com/fredoly
http://www.cardomain.com/ride/2412127