On taking mine apart I broke the in gear micro-switch when putting it back together. It sort of gets sheared off just as you'll finally fitting back the main casing - and the last drop of rain manages to put your fag out and your cup of tea falls over into your socket set.
Anyway my point being, Maplins sell them all for a couple of quid. Low Cost Standard Microswitches : Micro Switches : Maplin Electronics
A good idea though to make wiring simpler by taking wiring outside casing. I'm thinking to put a simple waterproof toggle switch to operate tilt and trim on consul, as now having intermittent problems with switch in handle.