Roadster to Roadster pickup

[midgetracer]

I purchased a 1930 roadster with a very nice cowl section, but the back has been cut out for a home made pickup box. Has anyone converted a roadster to a roadster pickup? i have thought about buying a roadster pickup back or extended back from Brookville. I may make it a bit non original to keep the cost reasonable. Will the subrails work if I shorten then? Any help would be appreciated. Repacing all the roadster parts to return it to a roadster car would be cost prohibited.