Funny you should ask.
I recently wrote to Revell USA and asked what was the prototype make brand and model the trailer was based on.
The response was that they didn't know. No one currently employed at Revell USA worked on that project.
I then wrote Revell of Germany and the head of project development at Revell Germany said he remembered the original project.
He was directly involved in the kit.
It was first offered in 1983 and was developed at Revell, when they were located in Venice, California.
The masters were tooled at what was then a brand new shop in Denmark.
He said when Revell relocated from Venice to Des Plains, Illinois, the original documentation on the model project was lost.
He did say he thought the model was actually based on a number of different trailer prototypes.
The original kit was offered as a stand alone kit (7424) and as a combination kit with trailer and Kenworth K100 Aerodyne (7432).