Just to let you know the outcome for those that are interested? Battery and alternator were fine. Turned out to be the started motor sticking because the garage where I got it serviced forgot to put on the earth strap when they where replacing the clutch. (didn't mention the clutch because I didn't think it was relevant) Mighty relieved as I just forked out £635 for a new clutch PHEW!
Marky I remember seeing a problem like that on my grandads maxi many years ago, he was puzzled why throttle and choke cables were smoking after it wouldnt start, hopefully yours hasnt sustained any similar damage.