Framebuilders - fork braze-on for dynamo lamp?

I'm going to be having a custom frame and fork built, and one of the features I'm looking for is a braze-on (and possibly two) for mounting a lamp on the fork. I'll be using a dynamo hub, so I don't want the bracket for the dynamo. Does this kind of thing need to be fabricated from scratch or are they available somewhere, and if it does need to be fabricated, does anyone know what the correct threading should be to work with modern lamps? Sorry if this is a dumb question. Here is an example. Sorry for the size.

http://www.blackbirdsf.org/taylor/images/4906/4906.jpg

For real custom work your best deal is to acquire the lamp in question before you get to the frame build. Often there is a tedency to wait till the frame is done before comiting to parts, and these days products change at a blistering rate, but if you do that you end up with ugly brackets like the one on the lovely frame.

Also fork mounted lights go back to pre-front rack days. You might want to look at sakkit racks for an alternative approach. This gets your light out in front of your bags, and off your handlebar. http://www.coinet.com/~beckman/frontrk.jpg. You can find some other pictures of Sakkits on the web, thogh not too many.

I have several dynamo style lamps and they all have different styles of attachment. The one I use most bolts onto a steel front reflector mount using a clamf lamp.. My Hella lamp uses a one-sided plastic mount with a notched anti-rotation device moulded in.
Fork brazeons are useful for extra lamps but I prefer a central brake-bolt mounting. It is better protected, higher up and replaceable with a different style of lamp.

If you are using a dynohub you may want to consider some form of wire routing brazeons.