Valve cover style appears to be ST, and you are absolutely right about the original data-plate location being on the fuel pump cover. I should be more careful about dashing off these responses.
In my experience, more often than not, the serial is NOT stamped in the flywheels. There may have been some date ranges where this was done consistently, and certainly many that were not.
That IS very good and concise instruction about identifying which S series - just from the valve cover design and exposed or hidden studs.
Thanks for your input!!!
dieselgman