"Ignition on, engine off: 3.5 volts or 70% duty cycle steady"
Indicates Federal version -- Okay
"Ignition on , engine running and hot: steady 1 volt or 90% duty cycle"
Indicates a fault but you need the CD-ROM in order to determine the specific cause.
"The same measurements on my '86 300E (103.983 non-CA engine) were 70% when engine off and hovering 50% (7 volts) when engine running which I think it's normal."
You are correct.