A few pics from the final version of my A1302 based hall effect pot replacement:
The first picture shows the control arm mounting plates that I made - they press-fit onto the pen body. They're VERY tight.
The second pic shows the completed assemblies with the control arms installed.
The third pic shows them installed in the Jentron MK2 gimbal. The original pots would jitter around center anywhere from 200 to 400 points. These hall effect replacements are rock solid. No jitter or spiking at ALL. They're stupidly easy to make too!