Re:
Ar, sorry- I got the wrong end of the stick completely. I had this vision of a huge 20mm QR!
I guess you could have inserts made for the fork that had a recess for the end of a 9mm axle. One could be permanently fixed, the other pushed in from the outside to hold the wheel. A long QR could then be made to hold the whole lot together.
However, unless you have access to lathes, it would probably be cheaper to find a new front wheel.- Which will work much better as it will stiffen the fork legs.