I actually am not sure what semi-truck it is. I've had the cab around my workshop for some time. I think I will use it on this tractor but I also have a '53 Mack cab that will fit, too, and a Freightliner cab over I was thinking of using, too. However, this looks really good, I think.
The trailer body is an unmodified New Ray trailer box from the ubiquitous offerings of 18 wheelers for about $20 complete.