Semi OT: Anyone know where I can find...
Christopher Fitch Memphis
...some of these?

I'm making a routing jig and I need four of these slotted plates but I can't find them nor can I figure out the right search term to find them via a Google search.
I'm a bit surprised because it would seem these should be easy to find but I've had no luck.
Related, here's the video of the person making one. His channel on youtube is very nice.