I do not know what the Pertronix wants. I do not know if your timing light setup is accurate. I do not know if your vacuum advance is operating correctly. There are reasons your motor will run good at the settings you described due to wear and tear of components, Germany gas, altitude, etc.
For stock 1955.2 6 cyl motor and ignition, Shop manual says pointer on ball. Plugs at .035. Octane at zero.
If ball is left of pointer, you are at retarded position. Ball is at TDC. Timing should be set at TDC.
If you turn the distributor in the opposite direction of the rotor rotation, you will advance spark. A Chevy dizzy rotor rotates CW.
Don't take this the wrong way but, you are not on the ball and you are retarded.
