While I was vacationing up in Colorado last summer I think I saw what you are talking about. This was a White 3500 pulling a long Patio Hauler.
I went and tried to see where it was built but no luck. I tried to remember what was on the manufactor sticker but mind and old age just dont work like it use to. The only information that I can barely remember is that it might be made in either Kansas or Missouri. Maybe one of our TDR members might have a clue on who the Manufactor is?
When I went out the next morning to get the info, they had slipped out early and I missed my chance to talk to the owner.
I tried the Adbrook cover, It is sitting in the shop. It was hard to hook up and the rain got in the bed compartment. It just didnt fit my bill.
Barry