Maybe something like this? http://www.twofish.biz/bike.html

I have two of these on my touring bike (the frame did not originally come with bosses, and the tubing was too thin to add any without damage).

They're not perfect, but they work. The strap is velcro, so I'd reckon you can cinch it down enough to fit the forks; that said, you might need to do some modifying.