In case it helps, on my Outfitter (equipped with Norcold 300 unit) the most common issues with the refrigerator:
1) Spiders love to nest in the gas lines and clog orifice, resulting in less than optimum fuel/temp. Inspect, clean lines if necessary.
2) The vertical "tube" chimney above the flame is subject to corrosion, rust build-up, which hinders heat transfer. Use pipe cleaners to clean out rust.
3) Stock thermocouple placement is pretty good. But once while troubleshooting I removed it, cleaned off built-up corrosion and made sure it was inserted properly to sense flame, and proper operation was restored.
4) Not applicable in this case; but I discovered (the hard way) that if 110 VAC hot and neutral leads are reversed (as they were in my camper) the unit will not work on 110 VAC. It makes sense to see of the unit still works OK on 110VAC?
I agree if you had an ammonia leak you probably would've smelled it; so hopefully something not as serious?