If you look at the back of the 1200 series you will find the coils and fins are not much bigger than your 6-7 and it's twice as big. The Amish replacement cooling unit is much bigger but even it struggled in hot weather. Without a third fan on the back milk would spoil. Yes I decreased the air gap on the back so all the air went over the coils and fins. Fortunately mine was not in a slide.
Tweaking was turning it off every two days so it would not go into the defrost cycle and warm up. This requires that you have a pair of computer fans that you move to various positions on the fins to remove the ice buildup. Any hot leftovers had to be left out until they cooled down.
There are some downsides to a residential refer...besides ice cream being hard to scoop out, I drink more beer as I do not like luke cold beer.
