Thanks for the info on the trailer !!
Jwaller said it was airforce . The data tag says 1-84 its made by Vulcan.
Yup Vulcan made many of the Bravo trailer's for the AF. The reg number was most likely 84BXXXX with the X's being the last four of the trailers S/N. Depending on when it left the AF inventory it may have been five X's as LRS has changed from 7 to 8 character reg numbers in the last 2-3 years.
Good trailer some of them had some very strange loading diagrams. The 7Q trailers were definitely particular on loads. We had a lot of problems with the 85B's and the 89X (7Q trailers) and frame welds a decade ago. So much so that the AF along with the DOD went and bought hundreds of Super trailers after the successful test in 05'. Needless to say after years of building, purchase, and running the Nuclear certification gauntlet they were delivered to units. Only to discover at the field level they had critical weld issues at the joints. They are now condemned from use DOD wide for Nuclear use.
I'm hoping they start popping up on GL. They were really great trailers but a hasty production schedule and poor welds seams to have lead to some critical production errors. I don't doubt they would be a great trailer for what I myself and you seam to be doing with them.
As for your use, I have a similar need in mind. I own a construction company, still getting my feet dirty. However it would be nice to have some earth moving equipment for landscape and foundation work. I intend to use the M915A1/M871 combo for bulk material handling. Even though a GN will accomplish my current needs I sorta wanted another MV.