Leon has a new Norcold N611 scratch & dent for $75 more than it would cost me to have him change the cooling unit on the 662.
I'm going to go this option for now. It gives us all new parts, direct fit replacement, and half the time to change over than if I had him refurbish the 25 year old fridge. Any option to get this done later at home would certainly involve shipping costs and hassle. I doubt I'd get a similar price. And I'd be doing the job myself...
I'm really liking the thought of a 12V compressor unit but that's going to have to be a long term plan for costs and energy calculations, sizing so I can apply the recommended insulation, etc.
Again - I am really thankful that people spoke up with so many good ideas.