Open to all.
Note that this isn't my puzzle
and I haven't attempted to find the solution. Therefore, I can't answer any of your questions and you must provide proof with the solution to earn the point.
EDIT: I found the solution, so feel free to ask questions.
To earn the point, you must identify the following (no proof required):
- sleeper cab manufacturer
- sleeper cab model designation
- year and make of the intended chassis