As Trev said, I think what you need to do is establish a "typical" load and if that includes 2 people and a full tank of fuel, six big toolboxes four jerricans and a trolley jack, then include that. I think if you get stopped then it will be the plated weights that will be used, so regardless of whether the vehicles and trailers are modified or not, if the plate says the vehicle is maximum 3050kg (for a 110) thats what they will expect.