Problem solved!
Knew I had gas. Obviously had air. Only think left was spark.
Previously tested the spark by a helper holding the sparkplug to the block while I cranked it over and him confirming I had spark. Quality of spark I didn't question. It has a Pertronix unit on it and in reading through the trouble shooting guide one of the causes of a no start is resistance in the ignition wire and it explained how to "jump' the wire to test for this. Followed the directions for jumping it and it fired right off.
Disconnected and cleaned all the connections from the battery to the solenoid to the horn relay, etc. Everything was tight and looked clean while taking it apart but after hooking everything back up it started right away with the turn of the key.
So some minor corrosion somewhere was preventing preventing a good spark and the starting fluid (or gas) would provide enough in the cylinder to get it to start with the weak spark.
Tried to start it with a hot engine, no problem. Starting after it has sat for a few days, no problem. Hopefully problem solved. Sadly after all these years of frustration it was caused by a simple problem.