I took a chance today, deleted the problem SSD boot drive. Apple HT process of elimination earlier showed it as the culprit. Re-installed SL from disk, then backed up with a suitable date from Time Machine. Worked surprisingly well- never used TM before. Some PAsswords were lost and the bookmarks lost their little symbols until they were opened again.
I have another internal drive coming- 2TB of WD Black goodness that I'll back up everything on again, especially the OS. Would this drive have to be partioned for each of the 3 disks backing up on it? Would CCC be of use here?
I also have another SSD ordered and on the way as a replacement in case I have another problem sooner than later- I don't trust the older Intel ssd I have. The Apple tech support guys I spoke to were split on the problem, 1/2 said HD problem and 1/2 said OS for sure.
Looking back to when the grey screen problem started, We seem to recall maybe trying to start/stop the computer when it MAY have been asleep. (it was very early in the morning) It's not clear, but could improperly shutting down the computer cause the OS to fail?