The 1100 Cab - 1/25th scale
In the 1972 brochure "Conventionals" and in the 1975 "Class of the Industry" brochure, Peterbilt displayed the 1100 Series Conventional Cab in a shell-only photo spread. The cab was only partially built, with the then-new cab features highlighted in red.

The photo was taken on the lawn at the old Newark headquarters in 1972.
The brochure had several different views 
I was bored one evening, I really wanted to build something, but didn't want to start a new project, and wasn't in the mood to finish a current one. I was rummaging through a parts box when I came across a couple of AMT Peterbilt 359 kit cabs. Just the cab and firewall (and one cab with a nasty gouge in the passenger door and cowlside). I had used the rest of the kit for a donor platform for a 362 or someother Pete. This is when the idea hit me. How about making the cab shell? Hmmmm. I dug up the 2 needed brochures and set out to studying the photos.
I took the AMT cab with the gouged door, cut out the center of the roof, the doors, the vent doors, the top of the cowl and the original firewall panel. With strips of scrap plastic, Evergreen and Plastruct channels I made all the rear wall bracing, the roof bracing and supports, the door sills/jambs, the instrument panel support, the header and the firewall. I drilled 4 holes into the firewall/cowl as the real one would have. I cut the header for the AM/FM radio and the opening for the low-air wig-wag. I sanded off the incorrect roof cap and rear wall seams that AMT molded in.
A quick shot of primer and white (I didn't have a bright enough silver on hand to replicate the color in the photos), then painted the braces and jambs red.
Here's the model cab on the photo.
My door jamb could have had one more layer of plastic strips added for the
proper bulkhead look.
The real firewall looks wider due to the camera angle and lense that I use for
photographing models.
I couldn't get the same camera angle as the real photo.
My cab shell with the stock AMT cab.
Not bad for a 3 hour, no cost project! Granted it will never be on a chassis, or have fancy paint or chrome, but it's still a model!
Since I did the 1100 cab, why not do a 379 cab..
Slicing and Dicing an AMT 359 cab
Bored the last day or so, and convinced that I could make a Peterbilt 379 cab out of an AMT Peterbilt 359 cab... I commenced to slicing on two AMT cabs.
http://tahlborn.web.aplus.net/PB.htm