Minime:

A small pipe cutter, and a tap and dye set should do it. The problem is that the tap set will set you back some $$$. Do you have any contacts that are plumbers, mechanics or machinists? They may have the basic kit and possibly the taps to get to that size. If all else fails, call your local high school and see if they have a metal shop. Sometimes a shop teacher will do a small job like this for you.

For convenience you might want to consider using a short bolt or allen screw for the plug end. This will be one less thing to worry about and will give the machinist a target for size and thread type.


Chris