sulfur dioxide vs freon...
I have been told by several old time refrigeration men so2 and freon are compatable. im sure the pressure readings are a little different, John Jowers at antique appliances .com can tell you for sure, if this is like most of the old Coldspots, it will have a tag somewhere saying Seeger Refrigerator Co...Evansville Indiana,as far as I know they made all Coldspots until Whirlpool bought them out in 57.