We may never know what was the problem, precisely.
The valve cover came off, the ladder came off, the cams came back out, and the clutch cover came off (this last, primarily for unambiguous view of the timing marks), and effectively
@warp9.9 started over.
He blessedly stopped a number of times to consider my questions, and answer thoughtfully. The service manual was consulted a number of times.
All that said, the timing all looked the same to me, leaving me still in the dark as to what was.
Coolant and oil was added, Tune ECU connected, fan test, stepper motor, no codes.
Pushed the starter, and it started right up, as if it had always been so.
I did a small dance for joy, and have a gremlin in the form of a vacuum leak or such to chase down, and should be on the road.
Thank you all, for all your support.