I snapped the tabs off by hand, then threw the bracket on the belt sander to clean up the edges.
Then I tapped the holes:
Success!
While my original design has the spacers built into the bracket as one part, I couldn't justify all the wasted material to carve this from one big block of aluminum. That's why the spacers were cut separately. Not as elegant, but way cheaper and faster.
New build thread for the new machine:
https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/fun-with-a-6040-cnc-router/
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