In the middle of clean up here after a massive flood took out everything so all my records etc. have been lost.

From memory if you change the 18ohm 5 watt resistor to 39ohm 5 watt
the 330ohm 1/4w resistor to 560ohm 1/4w

then I think that should probably do it.
Maybe change to two 470 ohm 1/4 to something higher as well say to 1.0K
You will have to try the latter and see.

As for the hall effect the original was Allegro uA3240 but that is not made any longer.
Replacement for that is Allegro uA1120 I believe.

Remember small capacitor on the hall effect should be mounted right on the hall effect (not on the circuit board some distance away)

Pulse coil will require a different arrangement and I really do not have any spare time at the moment to work it out. (probably for the next 12 months or so)

Hope that helps....cheers