Many thanks to all who have replied to my queries.
I value your collective experience, training, and advice.

I want to be as certain as possible about the Crank Position Sensor; $150 isn't peanuts.

I checked AC voltage at Crank Position Sensor terminal (while cranking) and it measured 0.6 VAC. I started the engine and just let it run at idle; it eventually began to stumble and shut off after 15-20 minutes. Would not restart. I measured the CPS again. Resistance was 900 ohms (compared to 800 ohms cold). AC voltage was still 0.6 VAC.

I read in another thread (vehicle was a 1990 190E) of CPS voltage actual 2-3 VAC and spec 1-1.5 VAC. Is it valid to compare my numbers against those?

Is this the definitive proof that my crankshaft position sensor is faulty?