I was able to get each wheel weight on my RV by first checking the front right wheel, then the right side, and then the whole RV. By subracting the right side from the left, I was able to get the left side weight, then subtract out the right front, was able to get the left front, and left rear weights. Right front - right side = right rear weight.
I checked mine at a local moving van company. First I went in with my car, and asked the scale weight price, looked for a good way to drive in and out, and then came back with the 30' RV.
One reason to worry is a brand of RV that used to be built in Southern California had a problem with it's front ends. One side was much heavier than the other, leading to a overloaded left front tire and rim. So the manufacture recalled all their motorhomes, re-rated the rim and changed the front tires from 19.5" G tires to 19.5" H tires. Re-rated the front axle for more weight. Still had 600 more pounds on the left tire than the right front tire, but now was under the GAWR, tire and rim weight ratings. Out of the factory, the tires and rims where over the weight rating on the left side, but about 400 pounds under the rating on the passenger side.
Fred.