throttle mod? are you talking about removing the detent on the collective stick?

anyways, finding micro sized hardware is not easy. in fact i've had troubles finding a common mounting screw for the popular gws ips motors that everyone on the planet is using. your best bet is to dig in your boxes and see if you can find one that fits. if it's tapped in plastic, almost any similar screw will work. if it's a machine screw, well...