This method turned out really well, so I thought I’d share some pictures. I used an electric knife to do the cutting. Squeezing the foam between boards gave me a great guide for cutting nice straight lines.
Hi BloodSyphon,
I’m impressed … you cut foam like a professional 
Thanks for sharing the pictures … they’re great.
Phoenix
What a amazing idea! You think like a Pro. Wonderful share and idea.
Really impressed!