it's nice to see progress is being made ! but one thing jumps out at me concerning your trailer hitch. in using what amounts to be an open channel, it seems that opens up a good opportunity for a twisting, or a collapse of the drop due to insufficient gusseting, even though it appears to be made of thick enough [1/4" ?] material. and even if the trailer is a light loaded deal, i have seen similar setups twist up like a pretzel during my brothers stint as a "gofer" for the local u-haul dealer in his younger years. you have done excellent work so far, so please don't take this as a slam. i sure would hate to see anything happen when you are done, then have to go back and re do the hitch.