Yes, it is possible to mount the "german style" clamp nuts...
BUT:
You also have to mount the specially formed trust washer/guard plate and also change the grease caps to the old ones, as the clamp nut needs a little more space in the hub. The original cap fits IN the hub, the old one fits OVER the hub.
Setting the bearing clearence will get much more comfortable and precise, so it's worth the afford.
Greetings from spargelix
Edit:
guard plate:
http://www.csp-shop.de/cgi-bin/cshop/fr ... ort=0&all=clamp nut:
http://www.csp-shop.de/cgi-bin/cshop/fr ... ort=0&all=grease cup:
http://www.csp-shop.de/cgi-bin/cshop/fr ... ort=0&all=