Wow, thanks for remembering the fuse and countless sleepless nights......when it failed the MOT it was found (now don't laugh) that the bulb filament was actually faulty and was only working occasionally. New bulb and all seem ok

to the untrained eye it deceivingly looked functional, intact and in fact was a new hence why I discounted it from my investigations
Bout my new electrical woes, seems you beat me to it!! just checked under the headset in between fire calls (rather cats up trees) and it would appear that there may be a break in the wire from the switch to where they connect to the loom which is affected when the gear shift in and around 4th gear. Obviously stretching the wire and giving intermittent power.
So it'll be switch out when I get home, test for breaks, repair and rewire as you've suggested around the gearshaft. This should hopefully prevent it stretching and breaking again
Ain't much room though under there is there...tight as foo*!! :shocking:
Cheers again bro
Ash