Well I couldnt wait any longer knowing you were all in suspense. I stripped
and cleaned all the bits and then re- assembled it in the correct way and it
all went together fine. The fixed cup screwed in on its left hand thread and
the adjustable cup right handy ways. The threads in the bracket look fine.
The left hand crank is toast. It had worked loose and had been shimmed.
There was masses of grease in there so it all came apart easily. I have
taken some closeup photos and will add them to the set on flickr. I will
post a link later.
Mark Stevens much relieved in Evanton Scotland -- but still unsure how it happened and why?