Many thanks to Cabinet Guy for this information and pictures.

Our trailer originally had a typical icebox with neat Deco hinges and latch. We really wanted a fridge and considered a 12v/120v Rv fridge but couldn't quite swallow the price for new ones. A used one was ruled out because I didn't want to buy someone else's problem. We settled on a small 120v dorm type fridge from Costco for under $100. Our rationale was that we could plug it in at home the night before we left and if we kept the door closed it would probably stay fairly cold until we got to wherever we were camping and plugged it back in. If we were camping without electric hookup we would just use it as an icebox. Not as nice in that scenario as a 12v version, but the cost difference didn't make sense for us. Now the challenge was how to make a modern fridge look like an icebox. This is what I started with.

 I took the door off the fridge and added a face-frame which I trimmed on the inside with angle aluminum so as not to have any exposed wood  inside the fridge. That was the easy part.

The door was a head-scratcher. I laminated up a 3/4" thick panel for the door and ran a 1" wide rabbit around the edges. I also added a strip of 1/2" plywood around the raised portion.

I cut, hacked, chiseled, pried, cussed, hacked some more, scraped, cussed some more and was finally able to get the plastic inside of the fridge door off amazingly in one piece! They obviously didn't plan on anyone taking it apart. That was a job!

I attached the plastic to the back of the door and trimmed it all out in angle aluminum. Next I added weatherstripping. 

After cleaning up the original hinges and latch and installing them on the door, I installed the door onto the face-frame on the fridge. The whole unit was slid into the cabinet opening and fastened in. Here's a couple shots of it installed.

All in all - I'm really happy with how it turned out.