Thanks for all the responses. The brakes are apparently Mafac 'Driver'. The
general consensus is that I should hope that the bracket is either French or
Italian. These have right hand threads on both sides so I should be able to
swap them over. The spanner flats on the fixed cup look smooth and crisp so
I hope that it has not been forced in against it's will. I will strip the
bracket soon and let you all know the outcome.
Mark Stevens Evanton Scotland