2619 AC Duct Work Location

I recently purchased a 2004 model 2619 that has a side AC installed directly across from the bathroom (see picture). It must have been ordered without the roof mounted unit as there is no hole / skylight where it would have gone. We tested the unit out, with the kids, one night at home and the AC did not cool the unit very well despite blowing fairly cold air. It seemed like it might actually have been cooler outside then it was in.

The next day while finishing cleaning I noticed that there was light inside the cabinets behind and in front of the AC unit from cutouts to vent the AC. This is when I realized that someone installed a window ac in this unit instead of a through wall AC and it was puling air from inside the unit to cool the condenser side of the AC.

I have looked at all the posts here and searched online for either another way to vent the unit by pulling in outside air or a wall unit that will fit but no luck. This weekend I am going to pull the AC out and see if I can come up with a solution. It would be easy to vent to the outside wall if it was in one of the other cabinets but the wheel well on the front side and storage draws on the back make it nearly impossible. I am unwilling to part with a draw and cutting into the wheel well seems like a bad place for a vent that would gather debris.

The best solution I have come up with so far would be to cut a hole straight down under the unit and cut part of the tray off the bottom of that AC unit. This would let air in from under the camper but I would have to make a trap door to seal it up when traveling.