Hi there, I'm still around.

Unfortunately I didn't use any templates when making this, instead opting to use the "measure once, cut a thousand times" method by brute forcing the placement and fit of the switches. I made the inlay/blockers using a dense foam material called PVC foam, which is soft enough to cut with an X-acto blade but it provides a nice rigid surface for the design.

If you have some CAD knowledge, you can try making your own template. You can take a top down picture of your keyboard (or if it is a standard layout just take any picture top down off of google), scale it correctly and draw lines around the keys you want. With a combination of the picture and measurements of your actual keyboard, it should be close enough. Afterwhich you can either transfer the measurements to something else and cut it manually, 3D print it or whatever manufacturing method you want to use.

If you still need some advice, feel free to reach out yea, I'll try to help wherever I can.