The link to the post I gave you is our own Cheoy Lee 41. Forget about using the original anythinig from your current fridge except maybe the door, you will spend more time any money
than it is worth. I made the interior
box from FRP available at home depot. It's inexpensive stuff and easy to work with. I used fiberglass
cloth to secure all the corners with west sytem epoxy
then painted the interior
with interthane white. My compressor is keel
cooled so it made it possible to locate it anywhere without consideration of air flow for cooling
. We also used the original main door with 4" of added insulation to it and new double seals
as door gaskets. The two top doors are premade from glacier bay if I remember right. They are not cheap
but work very well, light weight and seal very well. I highly advise having top opening access to keep the cold in as much as possible. One thing I would do differently if I did it again is to not have a spill over fan. I find that during the summer I get a fair amount of condensation
freezing on the evaporator plate in the freezer
which we must defrost monthly. I would separate the freezer and the fridge with a single
plate of stainless steel
and use insulation on the surface to adjust how much cooling
I would want to transfer from the freezer to the fridge. This way I could cut down on the ice build up in the freezer and keep the system running more efficiently. If I remember right, with the 2 new doors the box cost me about one boat unit for all the materials, the compressor system was additional to that figure. If you use an evaporator plate system, use the largest plate you can possible fit in the freezer.
I must say that having a good working fridge on a boat all season is a real blessing.