There are definite advantages to having threaded bosses on your fork blades!

When I needed to ride recumbents, I struggled to find a good place to mount a dynamo headlight. It appeared that a fork mounted light would be best, but I needed to create a mounting point.
My solution was to get a T-shaped bracket at the hardware store and attach the left and right side of the "T" to the fork blade with hose clamps, and use the bottom of the "T" to mount the light.
I wrapped old inner tube around the fork blade to protect it.
Here's the result...



It's not pretty, but it did work!

Steve in Peoria