Yesterday I got to the point where I could try a test start. I cranked it for awhile to build up the oil pressure (didn't have to do anything special since the fuel lines were empty and it would take awhile for the fuel to get to the engine). I tried some starter fluid and it started and ran briefly. I figured that it should have run enough to be getting fuel but it would not start without the starter fluid. I did a search on the forum (key word "starter fluid") which got me to a thread where it was suggested that the CPS (or as Porsche calls it the Crankshaft Reference Mark Sensor) might be the problem. I replaced the CPS with the one from my original engine and it started right up!
The problematic CPS has this chaffing which seems to have broken a wire:
Here is the second start up, since I didn't record the first one.
https://youtu.be/4oqefHMHm5c
It's a lot louder in real life... my neighbour was wondering what I was up to. I turned the engine off, it didn't stall. It seems that the car has to be driven to allow the engine control system to set itself up properly, so till then some rough running is to be expected