Quoted from mario_1_up:If you are going though the trouble of changing the lights I would replace the board for preventive maintenance.
I would recommend buying Martin's LED kit and keeping your original boards instead (until your original optos fail).
Williams optos are superior (and unavailable).
Besides, it's a $6 investment vs. $100 or so.
LMK if you decide otherwise--as I'll buy your old PCBs.