I'm going to date myself here, but my first big truck kit was the phantom AMT tractor and trailer produced in the early '60's. The model and image shown aren't mine, but this one was a local show last month. The first regular big rig kit that I built was the 1969 issued IMC kit 118 Dodge L700 tractor. The funny thing about this is that I didn't build it as a stock tractor, but instead built it as a box van using half of the IMC trailer kit for the box, and Plastruct to lengthen the frame and aluminum tube for the longer prop shaft. I still have this one after rebuilding it in 1974 to repair damage from a house move. My absolute oldest truck build was built in 1960 from original AMT kit 125 1925 Ford Model T double kit. I never glued the turtle deck with spare tire or pickup box onto that kit, so I could swap it out when I played with it. The picture shown of the car is the 1960 kit, while the roadster pickup is one I built strictly as a pickup around 1970.
Spoke with John G today at the toy show in Warren, and he confirmed that the tooling does exist. I mentioned how about offering it as a "parts pack" like they did with the chromed Mercury sleeper. He said that may be a possibility if there any demand. Use the email address in Casey's post and let them know. I also asked about the IH S-series trucks. He stated that they might have the tools but they still haven't been able to go through everything they bought. Again,, if there is demand, they might look harder to see if they have either or both sets of tooling.