RayChez
We had a Samsung197 in our S&B home for four years. Had the defrost issue and posted extensively to another forum on the fix. The issues is an aluminum tab wrapped around the defrost heater below the coil is too short to reach into the drain tube below. The fix is a $4. Part which had the extended tab or wrapping some copper wire in place of the short tab and extending it into the drain. Both are a DIY job however the fridge must defrost as there is likely ice frozen to a foam shroud behind the interior plastic panel will fracture if frozen when trying to remove it. There are no other defrost issues although some might claim the defrost heaters were replaced - likely by repair personnel not satisfied with the commission on a $4 part IMO.
While the RF197 is discontinued, Samsung make the RF-18 which is an updated model with a linear compressor that runs continually at variable speed as required so it draws slightly more power than the 197. There are few choices to replace the Norcold if you want a fridge that fits the opening. The Samsung fits almost exactly but might stick out an inch or two in front of the Norcold.
I went to an Amish unit but replaced it as the limitations of abortion technology limit its use in really hot weather with the sidewall venting on my coach. I moved the RF 197 from our home to the RV 18 momths ago against my wifes wishes. She will tell you today it was the best change we made to the RV. My advice is to get rid of the Norcold ASAP and you will never look back. Good luck,
Bob