As needles (and PU elements) for vintage B&O pick-ups are rare and pricy, i made a headshell that allows to mount a standard element. (in this case the Numark Groove Tool)
The position of the needle should be within 2mm of the original.

No

Yes

0.4 nozzle, 0.2 layer

25

smaller nozzle would be better. As would PET-G propably.

I'm using 12mm long, 1mm silver clad wire as pins to connect to the arm.
Space is limited and the closer to the arm the element is positioned, the better is the match of the needle position to the original. Therefore i solder the connections.
The pins receive some roughing up with pliers on the end that will be glued in the headshell.
You can straight them out again by rolling between two flat surfaces.
Solder the wires to the pins BEFORE you press them in the headshell.
With the groove tool element i will only use one negative (green or blue) Because they are linked together in the element AND inside the beogram and i do not like ground loops.

.............Perhaps i'll completely redesign the thing for more room with a horizontally angled head mount......
At the moment, if the element is slided completley towards the arm it should be mounted parallel. If completely away from the arm it is better to angle it 3deg. to disk center.