Firstly, Thankyou for your input Combustor, that Year of Manufacture looks much more in keeping with the appearance and condition of my unit, and ties in with what DGman believes
Magnicon,
re breathing, that is noted.
the whole overhung rotor discussion scares me, though logically looking at it, I know that this genset was probably used from new as the charging system for a remote radio transmitter, it was taken out of service its head done up and the whole unit put away for possible future use, I cant see where someone fiddling with its mechanical side would fit into this timeline and why would it be changed? Plus there is no visible evidence to support this.
Reason for series globe....NOTED
I can measure RPMs so will do so ASAP though today I am working for a friend so genset will have to wait till my return
I will check the residual output and report back, I will then be quizzing you on AVR's for sure (A? Voltage Regulator, I know I've heard of it in the past)