Thank you all for various suggestions. All very useful.
I have rebuilt it for now with a couple of salvaged good plastic bushes and a good spindle. Not really happy but it will do for now.
I think I will make up a swinging arm with another good spindle I have and use needle rollers (I have found some the right size and 20mm long so will use 2 on each side). I will certainly try making some on the lathe using that oil filled Nylon (thanks Bill for the two suggestions) although I will contact them and check if I should pump oil into the swinging arm rather than grease which is, I think, what destroyed the Oilite bushes and spindle. I certainly won't use metal bushes again.
I did find one place in Germany which still seems to sell the spindle for 33 Euros but do wonder if they actually have any as no one else has them or can get them now. I suspect that having my old ones metal sprayed and reground or sleeved is the only option when I finally run out of usable ones.
I was going to use the swinging arm off a project XBR I have in the garage waiting to be finished and sold but can't get the bolt out of the spindle. Must be rusted into the spindle! Not sure what to do about it really as no way to get heat on the bolt. Soaking it in penetrating oil but not hopeful. I'll probably just put it back together and make sure the new owner knows about it.
Yes Tony, I went to the early gatherings and was just looking at my original membership card the other day which I think is number 003!
The XBR I am using at the moment I have only had for 10 years but have all the ones I have owned. My first one got stolen and recovered and written off by the insurance (I bought it back and the swinging arm I have just fitted comes from that one). Number one had 15,000 miles when bought and 89,000 when written off. Number two had about 70,000 when bought and (if I remember correctly) 145,000 when the frame finally rusted through in several places. Number 3 came from a good friend Mark (who came on the very first club ride out a long long time ago) and was already at about 100,000 and finished with about 150,000. My current one was 60,000 when bought and now has 113,000. I rekon that over the last 25 years I have done about 250,000 miles on XBRs. Not one of them gave me any engine trouble at all except that I have had 3 spark plugs break off in the cylinder head due to salty water collecting and drying out on the plugs and rotting out the steel parts.
I love the XBR and wouldn't be without one now, luckily I still have many good spares left except things like exhaust systems which are rare and stupidly expensive.
I hope that when all this crazyness is over I can get to catch up with everyone again.
Thanks everyone for the help and support.
Richard.