I have a 2007 Newmar Dutch Star with a Dometic NDR 1292 refrigerator. We have owned this motor home for about 13 years and have had the cooling unit replaced on the refrig about 7 years ago. It failed to cool on electricity or gas last month and I took it to a shop that diagnosed a card failure. That may or may not have been the problem as I was sure tha the door gaskets were in bad shape and a new card was going to fix a dead horse. The gaskets were unobtainium. It was time to replace the unit.
I wanted to replace with a residential unit about the same size. I found a Whirlpool WRT112 which is about 12 cu ft, the same as the Dometic. The Whirlpool was about 8 inches narrower, two inches taller and Maybe three inches deeper than the older unit. Not a perfect fit but it could be dealt with. The depth difference was no problem as the doors stand proud about 2 inches from the surrounding cabinet and that is a good thing. The shop removed the old unit, and pretty well broke it down so it would fit out the door. No windshield removal required. The new unit is about 28 inches wide and fit through the door.
The strapped the new unit down with steel strap and a wood cross piece over the top and plugged it into the 110 volt plug used by the Dometic and connected the ice maker. The then turned the installation over to me as it needed to be framed in to match the existing cherry wood trim in the kitchen. I first used fiberglass insulation batting to seal the unit in on all four sides as the back of the compartment is exposed through the outside cooling pannel.
I framed the unit in with matching cherry wood and I think it matches well. Looks like an original unit now. Pic attached. Sorry, I cannot rotate the pic.
I still need to fit door locks, but we are ready to hit the road to Texas.