opened pending updates with plans to run them one at a time, checking identifier in between.booted into an About This Mac with correct El Capitan identifier.Wiped and used older version, no wifi, for a 2009 Mac Mini I had lying around.this booted into an About This Mac that was correct.wiped iMac again and used an older version of El Capitan to install OS, sure to NOT SIGN INTO MY WIFI so it didn't update.
Okay, might have at least a clue as to what's going on.
