Great job on the cutting and the write up OP! Guys, one thing that needs to be mentioned as I did not see it in any of the pages.......be careful with the material you are buying!!
I own a foam fabrication shop here in LA and do plenty of case work for Pelican as well as other companies (however mine is cut on a waterjet), and polyurethanes, or ethers, are highly flammable. Make sure you do one of two things, buy only flame retardant material, or do not stop while in the process of hot wiring the foam, or up in smoke it goes. Trust me, I almost burnt down my building several times when one of my automated hot wire tables motor went out while in the process of hot wiring.
Make sure you find out what material companies like Miller are selling you, and if you are unsure, PM me. The reps at Miller dont know much about the material, especially when it comes to the properties ( I supply them, they are just a distributor of my product).
Also, you can test the material by putting a lighter to it. It will burn, but if you remove the flame and it continues to burn, it is not flame retardant, so take extra precautions when hot wiring. If the fire goes out, you've got some good stuff (most likely 2# char ester. Ethers are no bueno, esters are FR.
Again OP, great job! Didn't mean to hijack, just want people to be aware. All it takes is somebody to interrupt while wiring, and the garage is toast.
Here is one I did, but using polyethylene, which is a closed cell material (water resistant)