Howdie!
I've gone the other way, converting a wide axle Magnesium wheel to narrow (18mm??) - so I dont see why not - just takes time and patience......
If you are going to all the trouble of changing the front end why not go for lighter marchesini wheels to get the full benefit, Ebay is your friend here and its such a good upgrade to do anyways....
heres the fun I had:
Marchesini - Update to first post - Ducati Sporting Club Message Board
Cheers - Frank