Ok! Back on track. Maybe! Hopefully! Geez, I really hope so anyhow.
Sump is slid back in place, and replumbed.
Sump return:
What I did was take the chop saw to the original bulkhead and then chipped off the bulkhead off the elbow piece so I wouldn't have to buy new 2" ball valve pieces. I had enough of the bulkhead left to re-use it, so I did.
It's just a low-profile bulkhead now. The threads are just long enough to clear through the 10mm glass and have about 2mm poking out under the thread nut.
And the skimmer is hooked up and plumbed:
Pardon the mess of wires .. I've not been worrying about the wiring until I was reasonably happy with the placement of "stuff" (skimmer, pumps, etc.) Cleaning up the wiring will be a job in itself, but for a later day.