In any case. Here is a good working hall pedal. .5v to 4v tested.
Should work in any Gem as fs1 uses dry contact relay. T1-T5 ok. T1 may require 12v to 5v reducer which I can supply and test for you.
$200 or try a search. I have not been able to find or price it. My source is unknown. Let me know what you find.
