Brett.. If your old board was more stable with the windings you have, I'd use it.. My circuit was designed around the toroid and specific windings I used. If assembled with those specs it's stable also. I have 14 of them sitting on my work bench and all operate exactly the same. Switching back and forth between the 680 ohm to positive for direct hall input and then back to the 150 ohm for the timer board presented no bad habits on any of them.

John