Circled centre - alternator top left - starter and solenoid immediate forground. It can be reached without removing anything - but since I was giving this engine the once over, I took off the starter - just in case I ever 'had' to take it off - then it is a whole lot easier - especially to clean up the flange for a new gasket.

Below -

starter off - zinc removed. There was 'nothing' left of my zinc - just the metal stub to which it was fixed. I doubt if it had ever been looked at. This might account for some pitting around the lower cover - below the alternator, on an otherwise pretty clean engine for it's years.