There were several recalls on the Norcold 1200 series. They are poorly made and had thin tubing walls, which could crack, leak, and start a raging fire. They had at least 3 recalls, which did nothing to address the problem of bad design. Many RV'ers had their RVs burst into flame driving down the road. Some died in bed.
I'd trash it and buy a new coil set from the Amish. Youtube videos will show you how to change it or any competent Mobile Tech will do it.
If the interior of the refer is trashed, get a new one and many iRV2 members will come along soon with recommendations. But don't buy a used 1200. Maybe a refurbished Amish unit would be okay though.
Norcold stalled, denied, denied there was even a problem for years, then came out with those lame fixes that often needed fixing themselves. And didn't actually help much. Eventually though, they LOST a class action suit and many people were compensated somewhat for their losses and expenses. Norcold was shameful throughout this entire situation.