Led counter

gearbox counter
new zealand
j123
hi all
i manufacture car gear boxes and have a selector drum of 42 mm dia.it has seven raised segments on it which are 10mm x 3mm wide and can vairy on the hieghts.i need a device to regester each segment depending on the gear selected.the maximum no of led lights will be 7 .the lights must not flicker when the drum is being turned or gets stuck between gears and they must only come on when the drum has the correct gear selected. the drum turns clockwise and anti clockwise depending on the gear selection.
could i get a kit made up or could i make my own.
thanks
brett