A milestone night and I now have flushabilities! My flush water valve has been replace and all systems are GO!
When my water valve stopped working, I purchased a new one. But I bought the wrong one - the one for the newer 'less-water-saver' models. I have an OLD one, and at Home Depot I was able to find the correct item for "Old High Water Tanks."
Now the new one has been installed and "a flushing we will go, go go!"