machining wheels for conical lug nuts

[Robb]

So, messing with things I probably shouldn't be messing with...

I have 2 old Torq Thrust wheels that have through holes for the old style lug nuts. I'd like to have them machined with a chamfer (about 13/16"wide, maybe 60 degrees?) to accept conical lug nuts.
I might be able to do this myself if I could find a 13/16 countersink bit (I can't) but would prefer someone doing this who knows what they were doing.
2 wheels, I would think this would be an easy job. Let me know if you know someone who can do this, or if I'm thinking wrong.

Robb