I'd love to know more about this. I can't tell how this is installed, but it looks like there's more AC not visible than visible. The closest match to your AC I could find is this, it looks like it may be a newer/different model than yours, but the control panel is about the same?
Amazon.com: SPT WA-9020E 9,000-BTU Portable Air Conditioner with Remote Control: Home & Kitchen
9000 BTU is more than I think I'd need in my 13', and the size and weight
are larger than I'd like. 16 by 16 by 30 inches, 72.6 lbs.
I'm thinking of something like this, but I'd rather find a small portable I can easily vent without major modifications. 15.2" x 16" x 12"; 36 pounds
Amazon.com: Frigidaire FRA054XT7 5,000 BTU Window-Mounted Mini Room Air Conditioner: Home & Kitchen
Also being able to move the portable over the axle
when towing and then putting it up front in use would be ideal. But I'm not finding any portables in the 5000 BTU, 36lb range.