So I've one that's a little off-the-wall LoL

I want to make a new spindle clamping knob for a very common imported spin indexer.

The thread is 12 mm 1.75, but the hole in the casting makes the knob very loose, a very sloppy fit.

I'm sure I can bore the hole and re-thread for the next larger size, but that's getting fairly big.

My off-the-wall thought is either thread milling or single point threading on the lathe, but starting with stock that is a bit larger than 12 mm.

Just wondering if anyone has ever tried this approach?

Terry