How to form the cab?

Ive been looking at ways of using available materials to form the cab, heres a photoshopped pic of the cab using the back 1/4 light section from the rear door, ths would give a ready cut glazzed secton behind the B pillar and a framework to form the rear panel above waist height. Once this is formed I will look at the possibility of using the upper tailgate as a hinged rear cab window.