Just a quick update. I'm waiting on my fresh water tanks to show up and in the meantime there is little to be done, but I did get a second LED ceiling light and replaced the first one with a new one, same model. The original was flickering and overheating, but the two I have now are perfect.
These are the lights I installed. Home Depot recently dropped the price on these to $29.88 (plus a 10% military vet discount, if you qualify):
About a week ago I found this chest freezer with bottom drawer on craigslist and picked it up for $140. This one is a bit larger than the 3.5 cu ft freezer I already have (I'll need two for my food chilling requirements). The drawer is designed to be a few degrees warmer than the top chest so you can keep deep freeze stuff on top and "soft freeze" stuff like ice cream in the drawer. Well, that may be fine when it's used as a freezer, but once converted to a refrigerator with my thermostat controller, the drawer doesn't really get any cooler than room temperature. That's no good. I'm thinking of selling it and getting a standard chest freezer.
I should also say that the air duct I installed for the air conditioner works beautifully and is much more efficient at getting cool air around the inside of the space. There is no longer a large difference between the temperature in the bed area and the front of the bus, and this will continue to improve as the duct is further constructed along the ceiling. Plus, the additional structure makes everything quieter and sitting in the bus with the AC on is very rewarding and serene. I could sit out there doing nothing for hours.