HI Bob,
I'm assuming from your part numbers that you have the early 7in. single sided hub ??
As here?
http://www.draganfly.co.uk/index.php/a65anda50/category/915-3-front-wheel-7-a-b-m-groupThe nut is right hand as its the same part number as the one on the brake plate
I would try bolting up the opposite end withe bearing and brake plate and tightening up the brake side nut tight, a spare nut would be useful as a locknut ???
Then try and loosen the other end?
If this fails, lock up the brake plate side nut again, take it and a suitable size socket to your local tyre depot and get them to use their rattle gun on it
Another way is maybe to remove the split sleeve from the LH fork leg and fit in the oposite end of the hollow sleeve, I think they are tha same size?? if they are, tighten the pinch bolt to lock the sleeve and spanner on the offending nut
HTH
John