Rex Speedshop may offer a used pickup but does not do repairs and has no new parts, at least that was the situation 2 years ago.
But as they work with Kedo there may be an opportunity for getting the pickup repair handled by them.
Kedo has a supplier who does rewind those pickups if you send a faulty unit (stator AND pickups all in one set) and order a complete overhaul.
This is the only easy solutiuon I know:
http://www.kedo.de/products/DL106-1.html
I did muse about building a pickup myself, but still having spares available it was not needed yet.
One could build a working bastard out of two single pickups with similar resistance values.
The nominal value is 115 Ohm plusminus 20%.
So about 100-140 ohms.
Furthermore it depends on the winding direction of the pickup coils, whether a positive or negative pulse is generated:
https://transmic.net/2016/07/14/yamaha/
The original CDI only works with the correct pulse polarity.
I have measured the 1VJ pickup:
Single inductive pickup with 128 Ohm P02 is available from motorcycle electrics suppliers e.g. Ignitech (CZ):
Then it is just a matter of mounting and testing ...
Open questions concern the (necessary?) potting, so that vibrations will not kill a bracket ... I would possibly trust JB Weld.
Also, to get the connections right, one would need an oscilloscope and a working sample pickup, or a small test rig to set the wire colors once in a trial. If the adjustment is incorrect, the motor can kick back and self-destruct due to the kickstarter lever retracting with force ...
Andy