Don't have it any more but my old lorry with a full tank of diesel and water weighed 6 tonne. I only every carried a max of 2 small horses or 2 natives so had plenty of weight for people and gear. When I had it built we were really careful to only put on board what we really needed and the builder used lightweight materials and "proper" lightweight caravan units for the living. The contract with the builder specified that is must not weigh more than 6t. I took it to the weigh bridge myself before paying the final installment
My last one weighed 5.3t but had the heaviest partitions ever, 2 people struggled with them. The one I have now Im told is 6t but that has to be confirmed