Thanks Dan O.
For some unknown reason the'48 defrosted itself. Also, I use it to
hold 2-10 gallon Cornelius kegs. I might open the 'fridge once every
couple of weeks to switch the beer line. It's always stay on #2 and it's
around 33'. I didn't know what the letters meant.
For older refrigerators with just a tiny freezer box, an absorption refrigerator thermostat usually has the closest temperature range. The only universal one of those i know of is a Ranco VA2. I don't know if you'll find one in the USA but that universal control line is popular elsewhere in the world (including here in Canada). The absorption refrigerator control replacement is not one of the most popular in the series.
The differential is wider than the VA2 which is 8 deg. The A30-180 might cause the fridge to get slightly too cold or slightly too warm before it cycled the compressor on or off. You might not notice though. Water might slightly freeze but then thaw by the time the control cycled again or it might have been in an extended off cycle when the drink was grabbed.
The wider differential is more suited to a full-width freezer box (ie. a more modern manual defrost refrigerator) but as I said, you might never notice.