Erm.. how about using an old drill bit (the shaft part obviously) and some aloxite and water to hand grind the chamfer- if you aint got that then use Valve Seating Abrasive. Note when grinding like this nice slow movement and constant but medium pressure works best. Take the shine off the drill shank first by sticking it upside- down in a drill and hand grinding with a 2"X1" thin sheet of aluminium and aloxite. Wash with soapy water.
Would take you about 5 mins per hole and could be done while the next part was being machined.
Hell, it's only to make it look nicer... hand chamfer it.. you can say in your company literature "Hand Finished by Professionals"
Iain.
[Edit]If you can't get the proper abrasive then goolge "Jeweling abrasive" or "Engine Turning"- the kits sell for about 6 dollars on E-Bay I beleive [/Edit]