After a bit more research I found this: The Velo ORANGE Blog: Converting From 26" to 650b

Velo Orange seem to think 26 inch to 650b works with Tektro CR720 brakes. I remain a little skeptical.
I'm going to look around in local bike shops for a suitable fork, but I'm not very confident I will find one with canti studs. Maybe it's time I learn how to braze?

Edit: I also found this: http://www.cyclingabout.com/converti...-touring-bike/

I'm starting to think I could make the 26 inch fork work with the Tektro brakes.