"following the daina description sentence by sentence - word by word with some added words by pinsiders" means: Unfortunately the manufacturers did not write a complete "start-up procedure" - we must add a couple of things.
Great - You toggle the main power switch -> Game-Over-Relay pulls in (and must keep-on pulling), U-First-Ball-Relay pulls-in (and must keep-on pulling). I hope they do.
You opted for "C-option" - so for a while You actuate manually the S-Start-Relay -> question: Does the S-Start-Relay lock-in for a while ? It should ...
Great, the Score-Motor starts to turn - it is a bit confusing - in Williams / Bally Pins we talk "a turn" - we mean: The Nylon-Wheels do turn 180 degree - half of a full revolution. In a Gottlieb pin we talk "a turn" - we mean: The horizontal turntable-like metal plate does turn 120 degree - one third of a full revolution. So Your Score-Motor start and does a (full / complete) turn - Great, the "Self-Hold-Switch on the Score-Motor "SCM-1C" works fine and makes the Score-Motor to complete the turn.
Great, the "Relay Banks" do reset. At the very bottom of Your "snippet of schema, post-22" I see a "Switch on S-Start-Relay CLOSING (nice)" and I see a "Switch-2C on Score-Motor CLOSING (nice) - then I see fuses (they are OK (fine)), the Coils for the "Reset of Banks".
I was asking some more questions:
DOES THE AX-RELAY starts pulling ? and keep-on pulling ? It should.
DOES THE R-HOLD-RELAY starts pulling ? and keep-on pulling ? It should.
Look in your snippet of schema -> on the left, above the middle -> the symbol of the Score-Motor (encircled M) -> go horizontally to the right -> many switches -> the rightmost is marked "(Score- ) Motor-1C - the mentioned above Self-Hold-Switch - it works.
To the left of SCM-1C I see a "Switch on AX-Relay" -> AX-RELAY MUST actuate -> so this switch (on AX-Relay) closing DOES KEEP THE MOTOR TURNING. AX-RELAY is IMPORTANT for resetting - IT MUST PULL.
A bit of "schema-reding" -> see the coil on S-Start-Relay -> a bit to the right -> downwards -> "Self-Hold-Switch named "S" -> to the right and down -> to the right -> right -> right -> up -> Score-Motor-Switch-2B -> right -> Anti-Cheat-Switch.
SO: As soon as the Score-Motor starts turning -> turns -> SCM-2B opens -> S-Start-Relay gets inactive -> Score-Motor turns and the stops. Does this succession happen in Your pin ?
I hope - in daina -> we have completed sentence-1, sentence-2, sentence-3 -> we are at the beginning of sentence-4: What does the AX-Relay do ?