I have that file and printed it out, used a caliper to confirm the scale, and plan on doing it, basically, the same way. I am planning on installing guides or rails internally to hold a sled for the board. Hopefully, I can get a good enough bond with JB weld to hold the sled guides inside the box. I machined buttons out of aluminum rod stock when I made them for my low mount tank DNA40, and that's still being worked on but slowly approaching completion.
I bookmarked that resource when it was first posted, Mike. Great resource! Thanks for organizing and maintaining it!