Small update.
Excepting the tubing holes, I wrapped up the interior trim panels. I can now finally say I'm ahead of where I was when I decided to start all over.
Pardon the dust, "shop shots" as it were:
On the immediate to-do list: Tear everything back out of there, fashion a final trim panel for mounting underneath the pump tray and PSU, rework the PSU chassis to properly hold the 140mm Xigmatech fan I shoe-horned into it, perform some minor surgery to the factory chassis to better accommodate the modified PSU, and sort the modifications I'm going to need to do to the pump tray to properly mount the pump and reservoir assembly.
<searches around for something caffeinated>
Getting close to actually installing some of my new hardware.
Kinda.