Lot's of time and effort put in, but still no luck with identification from this end 'm sorry to say
Have been focussing only on external unique physical attributes eg the design of the gearbox, skeg and exhaust outlet, the horizontal ribs in the fuel tank, the exhaust manifold etc and haven't found a match in any of those.
Probably a good thing I guess, because it means the chances of this outboard being a bitsa are reducing.
Will try some more later.
Regards,
Spiro