Update........ Well it happened again! About 50 miles the squeal came back and each ride it came back louder and stayed longer!
how frustrating!
I hope this will save the next member a few hours/days/$$$. Ready........
The culprit (probably all along) was a loose crank shaft belt. I know what you are thinking - why didn't you check that first? We did!! Both belts felt tight and the noise was heard in the water pump with the stethoscope.
Anyway, before we tore it down (again) we decided to adjust the lower crankshaft belt. There are 2 small adjustment screws on the top if the water pump. We removed the alternator belt from the alternator loosened the 4 water pump bolts (there will be some coolant that escapes) loosen two nuts on adjuster screws. Make the adjustment then tighten everything back up.
We started with one full turn of adjustment and 90% of the squeal was gone, made a half turn adjustment and 99% of the squeal is gone. I feel as though we have this "licked". I will put a few miles on the trike and probably make one more adjustment.
If the squeal returns we will take the advice of Stan and Tom to scuff the crank shaft pulley. I hope it doesn't come to this but I will keep you posted.
Thanks to everyone here for helping to solve this issue and special thanks to Rhonda, Stan and Tom.