Latest problem seems to be alternator based. Lights seemed dim, indicators only worked slowly when nothing else electrical was on and now the battery is down to 11.3 volts and will barely turn the starter.
Checked the alternator output and its only giving just over 11 volts! Belt seems tight and I've double checked the earth strap to the body.
I don't get a generator light but never have so assume the bulbs blown.
Any ideas much appreciated before I bring out the petrol and torch the bloody thing!