Our cart was built on a 6X12 trailer frame (we shortened it and moved the axles towards the front). The original trailer would “tilt”, when in the “down” position the front of the bed would pin to the trailer tongue.  When we put the trailer back together, instead of welding the tongue into place we kept the original pin and drilled another hole at the rear of the tongue and added another pin. this allows us to completely remove the trailer tongue from the cart.  We have had a couple of situations where this was needed. 

Lorna, Do you think you will ever put a Grill and fan system in the trailer ??????? hope all is well, we will have to have a cup of tea together some day……………BillyB