Our boat came with an icebox and an older portable fridge/freezer. it also had a tiny portable fridge/freezer that the previous owner had bought for just under $300 but he found he still needed it and while willing to pay for it, I just called it his. Anyway, the older Dometic fridge has been in the way and so I thought maybe I could convert the icebox. We have been using the dometic to freeze ice block packs to cool the ice box anyway.
However, icebox conversion kits are rather pricey at $1500 and I felt cheated just looking at the prices. So I came up with a cunning idea to buy an inexpensive portable compressor based freezer and use the innards of that instead. I am happy to say that my conversion cost just over $200CAD including the long shaft screw driver I needed to take it apart. Rather than a huge message here, The link to the project with it's pictures is Here.
Just in case someone else might be interested.
Note: I don't do fancy web pages :)