Would these work? The Sheldon Brown Fender Nuts. They allow you to mount the fender tab to the rear of the fork crown.

http://problemsolversbike.com/produc...n_fender_nuts/

I'm looking my bike with the SKS fenders, and it looks like mounting with the SBFN would move the tab back about an inch, which would lower the bottom of the fender about that. The addition of a mudflap should be enough to keep feet dry. And cheaper than new fenders, too.