Hi Mike, when I was installing mine (c&c38 '76), I realized that insulation was poor to none. Those cheap
production facilities and tight budgets!
Drilling holes in the icebox didn't turn out to be that bad. Didn't need to drill on the side facing the engine
I took the cabinet drawers out and added a bunch of blueboard, about 4-6 inches or so on the side facing the engine
, and anything I could add in the back. I used the expanding foam from home depot and sealed everything else. The performance was much better after I added that expendafoam through the holes in the icebox. I used the foam with medium expantion. a total of 1 can did the back and starboard side.
I also liked Richard Collemans reccomendation to put styrofoam packing material into ziplock bags and put them on top of the food
about 6 hours after my initial startup I had frozen medallias on the bottom of the fridge. This was Puerto Rico
Then the next day i had ice.