Yes, I'd found myway there before I'd asked for help,
and followed your path there as well...
...it's more of less the same page,
but mine certainly doesn't offer the
"DELETE BACK-UP" Option (or I'd have done so.)

edit:

As far as I know
I've NEVER Backed-Up my iPhone to iCloud
I've always selected Back-Up To My Computer

That might account for
the lack of the "Delete Back-Up" option

that leaves iTunes/Movies & iPhoto/CameraRoll
as the suspects... Any suggestions?
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"...or am I a butterfly dreaming she's a woman?"