Re the nut, I looked at all the big stuff, frame, suspension etc but could not see anything obvious, but it has got after market indicators on the front so that may be it.....hopefully. Thank you.
The bike is in bits at the moment, just finished a valve check (all good) and waiting for the oil and air filter to arrive so will check the voltage when more bits are back on.
I must say, so far it has been pretty easy to service compared to some bikes I've worked on, it is also my first v twin.