ok, still no spark unfortunately.

The starter turns just fine, plenty of juice.
Had partner crank motor over to check spark from coil, but nothing is
there.

1. checked voltage from negative coil to ground, 12V.
2. cranked engine until points were open, then checked negative coil to
ground, still 12V when points are open.

Does this mean the distributor is 'shorted', as the troubleshooting
guide in my Clymer manual suggests?

I checked the 'double relay' per the directions in Bentley and it turned
out to be just fine.