Got some more done tonight. I finished demolishing the ******** paneling, and took a good long look at the inside of the stand. Other than some old salt creep from my sump, I don't think there's much going on in here! I don't even think I need to shore it up....as I said, my father in law was an overengineer at heart.
The skinning was straightforward. Corners will be sanded and hidden, so I was able to make my cuts with a simple saber saw (don't do that if you want your joins to be seen!)
The opening for sump maintenance is nice a big. The current plan is still to use one piece to cover this, held on by clips at the bottom and magnets on the top.
Last pic for the night. Gotta go clean up now. I put the columns on here just to remind myself of the height of the tank.