You could mill one.
Today I used the PM-1660TL to shorten a bolt that I had in order to properly mount the DRO display.
You should be able to knock it out from the other side of the through hole with a wooden down or something.
I like how you put that .Love this, a perfect example of home machining, $15,000 of machine tools, $3 in materials, and 4 hours of labor to make a $2 item, well done.