I replaced the original fridge in my 66 Tradewind shortly after I bought it with an RM2500 mode (1984)l. This was a completely different fridge than the model 52 that it replaced, but it was an easy install as I just took the old one out and put the new (to me) one in. The only change was to add 12v
for operation of the RM2500.
The performance of this fridge since I installed it 3 years ago has been marginal. It will keep it in the 30's with it on max cooling position (#7) if it is below 80, but it will not keep it below 40 if the temp climbs much above 85 or higher. I generally keep a block of ice (1 gal) in the bottom when I start out to help it keep the fridge cool. I never turn the thermostat below max in the summer time.
I have read on these forums that lots of Airstream owners have had similar problems with inadequate cooling from the rv fridge and have added fans, both in the fridge and outside the fridge in the vent area behind the fridge to help the fridge keep cool.
I have also heard that baffling in the rear area may help cooling by forcing more airflow through the condenser.
I recently decided to replace the RM2500 fridge that was 29 years old with a new RM2510 fridge since I was not able to get the fridge to operate on gas recently and removing the fridge for maintenance is such a PITA. I am also planning on doing lots of camping in the future and want to minimize any problems.
I read the installation instructions for the new fridge and they recommend baffling behind the fridge to force the airflow over the coils and the condenser, and they recommend sealing the vent area behind the fridge to keep hot air and exhaust gases out of the trailer. The following two photos are taken from the installation manual. The most important points are: "All joints in the enclosure must be sealed to prevent gas leakage into the living area. The following maximum clearances specified are necessary for correct refrigerator performance: Rear 0" min to 1" max."
The 3rd photo shows a comparison between the condenser on the two fridges. The condenser appears to be about 1/3 larger on the new fridge (RM2510). This should also help fridge performance.