Thanks everyone!
Ross, I actually thought about that!
Turns out I also have the LV 1/2" and 1/4" and several fractional drill bits fit those nicely.
LBD:
I had originally tried a flat file but was getting nowhere. This diamond block was under $10 and already worn out. The four sides (200, 300, 400, & 600 grit IIRC) made for a great way to get a square cut in the metal while I slide the block back and forth on the table. The blocks edges still had some grit, but this work (no water) seemed to take care of that. Just another worn out tool that I kept around in case something came up (and it did!)
Fun thing about using drill index bits is many have the shanks turned down to 3/8" for bits > 3/8" diameter. Perfect since you can find a good fitting bit, then put it in shank first to mate up with a 3/8" Forstner depth hole.