[drover]

As always with these mysterious things first port of call is actually the battery, age means nothing nor does a voltage reading, get it load tested and see if it is actually still in good nick.................. I seem to recall this shifter light issue many, many moons ago in a thread, will see if I made a note of the issue.....
Throw a cleaner down the throat for the other issue and then go for a good burn, should get rid of the oil residue in the inlet plumbing and a good burn straight after should cook the muck out of the chimney system ...........