No spark

Great observation. Probably the best suspect is the roll pin has sheared off for the drive gear, (blue arrow). A clue is the engine will sound normal during cranking. Same if the teeth are worn down on the drive gear, (red arrow). Another possibility is the timing chain is broken or the teeth are broken off the camshaft sprocket. Those teeth are steel on replacement sprockets, but the originals usually had nylon teeth to make them quieter. While much less likely, the camshaft can break too. The clue is the engine will speed up intermittently during cranking due to some valves being open constantly. No compression will build up to slow the starter motor down to normal.

The last thing to consider is the distributor's shaft is a two-piece affair. At higher speeds the flyweights spin out and rotate the upper half of the shaft to advance the ignition timing. With any problem caused by the distributor, it is probably better to just replace the entire assembly rather than trying to find repair parts.

If the teeth are worn down on the drive gear, I'd suspect lax oil changes. If the roll pin is sheared off, one cause of that is excessive condensation inside the engine that froze and locked up the distributor's shaft. I ran into one of those many years ago.

Although uncommon, if the two-piece shaft has come apart, you'll likely still have some oil pressure during cranking. What looks like the flat blade of a screwdriver below the drive gear is what drives the oil pump. If the pump is still spinning during cranking, you could get enough oil pressure to turn the warning light off.