Thanks. I hope I did this correctly. Resultant SFCFix attached.
AVAST had been uninstalled / re-installed and repaired recently-prompted by my noticing it appearing in the pertinent logs. Even uninstalled, and after SUR, problem not resolved (sfc still didn't run). So I re-installed AVAST. Also didn't think those entries were the real problems, but then I don't know anything in this realm !
edit: I can def. confirm I had bad memory recently and ran the pc not aware of it. Memory removed and tested and remaining memory is fine.