UPDATE: LRIM1201fridge not cold, freezer is

My Norcold is 20 years old and I have had a number of issues with it to get it cooling again. One thing not discussed a lot on here is the burner tube slots rusting out over time. The slots get wider allowing a higher gas to air ratio which does not heat as well. Mine actually rusted out completely. I made a slider temporarily when on a trip like on a water heater to adjust the gas to air ratio. There was no direct replacement for the tube due to age so I had to flare the end of the input tube to the new burner which mad a big difference in starting the refer and cooling. The frost build up in you picture looked like mine. When I did the dollar bill test it was not sealing properly about a ft bellow the refer latch. There was no adjustment for the latch to make the seal compress more so I removed about .050 off of the back of the black plastic latch which allowed the seal to compress more and prevent the humid air from entering the refer. When I called Norcold on these issues they told me the only fix was a new refer.