[wdfifteen]

Looks like I’ll just have to try some stuff. There’s no magic bullet, but some good ideas here. As Zeke suggested, I’ll drill it for a 5mm screw and see what happens. There is a good chance I can get a 5mm tap through the hole as is. The part is made of some soft cast metal, Im thinking zinc alloy, so tapping it won’t be an issue. If it doesn’t hold I can order the replacements and drill one out. Or see if there’s room for a shaft collar, might get one that’s small enough OD too small ID and bore it out.

To hold it I may have to come up with something different from the drill press vice I have.