Thanks for the many informative responses: I apologize for not acknowledging them before: I am not receiving notifications for some reason - do I have to subscribe to a post I initiated??? My preferences are set to receive them.
I have decided to take hbn7hj
's advice and buy a new RM2354, in view of the age of the old one.
I have been thinking about the many complaints that Dometics don't cool well. I have not used the one I have: I am renovating a 1964 RoadTrek Popular, and I don't know how well the current reefer cooled.
I would not be surprised if they don't cool well in that model RoadTrek, because it only has one vent, and that is at the bottom of the reefer. There should be one at the top also, because heat rises and there is a lot of dead space for it to accumulate in.
Moreover it requires two vents for proper air circulation, one taking outside air in and the other exhausting hot air and that flow is likely to be sluggish. I plan to add the second vent, and any baffles that are necessary, and also install an extractor fan on the top vent to create a much more aggressive air flow, and better cooling. I may also add a smaller fan that draws outside air from the lower vent, and directs it across the cooling fins.
People who have added circulating fans often report excellent results, but they never say if they have dual vents: I expect that those who are the happiest with addition of a fan do have dual vents.