Great little web site.
Amazing, I did think the old connoisseur still existed. I used the BD1 turntable as part of my metalwork project back in 1972, but designed and built the arm from dural Al. with 3 bends creating an aggregate bend of 17 deg. ( I think); Gimble knife edge bearings for the vertical movement with a ball race dropped into a brass 'envelope' supported on an Al. spindle . All counter-weighted, adjustable and two different methods of biasing the centripetal forces
The hardest part was positioning the arm so that the pick up stayed more or less at a tangent when it crossed the tracks - all a bit of a hit and miss, so to speak, I gave up on the pick-up head since I struggled to get a suitable fixing of a flat steel plate onto a 1/4" dural pipe and bought a professional one.
It worked surprising well, as good as the Thorens deck I had later.
Thanks for bringing all that back to mind....