Fork end material mounted in the 4-jaw and having the boss turned on it – I used my height gauge to center the material in the chuck.

Scaring the poor 1/4 inch brass square to death in the milling machine.  Here I’m running a 3mm slot drill through to create the fork (or the tines, maybe)

The fork end after some trimming and filing.  I need to tap the 5ba thread into the boss to connect the valve rod.