Cheers mick, I did as you suggested and put a piece of foil in the slot, it doesnt buzz with the foil.
I think I do need a new nut tho because the nut slot for the .100 Estring is about the same size as the .130 b String? I really think it's rattling sideways.
Ps I fixed this blokes gas line on sunday, in his roof, in 39 degree heat, and i didn't charge him for it. He was selling the bass anyway I noticed him taking photo's of it, he was just about to put it on the internet.
PS the action is about 1mm at the nut and about 3mm at the 12th frett, reckon that sounds ok. I'm not a guru bass player but it looks pretty high? the neck has almost no releif in it, and it doesn't buzz at all anywhere else?
And the guitar makes that buzz all the time, plugged or unplugged.