I went through the same thing trying to fit a fridge into my boat even measured some with out the lid if it was possible to remove the lid and refit it inside.
Can you remove the lid and refit it once it inside ?
Another idea cut a hole in your deck close you where you drink and glass it in .
Have you measured your front hatch ? and can the lid be removed and refitted?
I stuffed around with all sorts of options trying to get a decent size fridge inside also Looked at what you have there as a ice box option dam boat makes it difficult .
At least I didn't get caught making some thing for the boat and not being able to get it in nearly did

Underground mining machines they cut them up on the surface and taken down and weld them together. When there worn out they drop them over the edge some where
It is fiberglass you could cut and glass it together once it down there