Thanks George. Sometimes it doesn't take much to confuse me.
This did it, came back from my shop with the wires to connect that extra capacitor. Then I looked at the wiring diagram again. The Run wire goes directly to L1, hidden interconnection on the black capacitor. Confirmed that with those resistance measurements you suggested.
Only the Start wire has the benefit of that 15 mfd capacitor. Did you mean in parallel to the Start cap? What you wrote was "wired in parallel with run cap", doesn't appear there is one.
Knowing nothing about these, I'm hesitant to experiment without expert help. Yours is appreciated.