OK, so I know very little about scopes... Perhaps, if I ask some questions others may jump in.
So, the item that interests me is the oscillations around the "missing tooth". They seem too "fuzzy" to generate a good reference for the ECU? Correct?
Also, from what I remember, the sensor is a hall sensor? However you've checked resistance which suggests it's an inductive? = AC The scope shows DC volts.... Now I'm really confused? Has some-one earthed the crank-sensor wiring?