OK  I solved the problem but I still can't explain why it happened. 
  
I was determined to look for the simple things so I decided to re-chack the gap on the new plugs I had installed while trying to slove this problem.  The misfires were at idle and slightly at part throttle with the old spark plugs and also the new colder plugs. 
  
When I pulled out the latest plugs tonight, they looked pretty nice.  But I noticed that the ground electrode completely covered the core.  I had been reading about side-gapping plugs in Grumpy's thread, so I decided to try it. 
  
I bent the ground tab up about 45 degrees, ground it about half way down on the bench grinder.  Cleaned up the end with a small file and re-gapped them.  Now the spark is going to have nice exposure to the combustion chamber.  I installed them, crossed my fingers and fired up the car.  Wow.  Smooth idle, no missing but, as the car warmed up, the idled settled a bit low.  I drove it, SUPER smooth power, and I came back and leaned out to idle mix from 10:1 to about 12.3:1 and it idles nice and smoothly. 
  
Hmm. 
  
This is NO B.S.  Side gapping works! 
http://performanceunlimited.com/documents/plugsidegapping.html 
  
My Alfa Romeo used to use Golden Lodge spark plugs that had four side gaps!  This was factory spec for Alfa in 1972!