A CAT scale should be able to do that in 1 pass.
For the local quarry scale, weigh the truck front axle, total, and rear axle without the trailer hooked up.
Go back to the scales with your trailer hooked up without changing anything in your truck. Now weigh the front axle of the truck by its self (front axle only on the scales) , the total truck with both axles on the scales without the trailer, with everything on the scales, and then just the trailer tires on the scales. The total of everything minus the initial truck weigh-in is the weight of the trailer alone. Subtract the truck alone weigh-in from the 2nd weigh-in from the truck only on the scales, and that will give you the hitch weight.......or take the total trailer calculated weight (total of all 2nd weigh in axles minus the truck) minus the trailer only axle weight.....that should also equal the hitch weight. The front axle weight with the trailer hooked up is easy....you already have that when the front axle only was on the scales. But you need to calculate to get the rear truck weight with the trailer hooked up. Take the total 2nd weights of the truck and subtract the 2nd weigh-in of the truck front axle.....that should be the rear axle weight. You can also take the total of everything 2nd weigh-in, minus the trailer axles and front axle of the truck, and come up with the same figure.
Are you confused yet ?? I think I am.
Chap , DW Joy, and Fur Baby Sango
2006 Ford F150 Super Cab 4x4
2008 Surveyor 263