What Nelly said, Ducati make it easy for you, shouldn't be beyond a decent machinist to knock up another stem that will allow you to adapt the Ducati yokes to your headstock/bearings
Many thanks for info. as always you help is invaluable.
So far i have managed to get the spacers made for the forks and had a 350ypvs rear wheel spindle addapted to fit front wheel. need now to get the wheel in and sort our spacers for the wheel and fingers crossed will be ok.
Fitting the yokes will now be easier now i know that the original is threaded as long as its not one of those funny sizes often found on the italian bikes.