The box was waiting for me onsite and I rebuilt the computer in the old case. They don't make nice cases like that anymore, but the cable routing was a PITA. The Z270 mATX board has the stacked edge-style SATA ports and there is not much clearance in that area for cables, so only three of the six SATA ports could be used. It was just enough since the two SSDs were removed from the system and replaced with the M.2 drive. The combo (3.5" and 2.5") hot-swap tray drives are on the Marvell adapter as previously.
The new PSU fit fine, though I think it is technically upside down. I also reused the Intel 1Gb NIC for the NAS. The USB 3.0 card was no longer necessary.
Unfortunately, the timing was never right for ordering the Noctual HSF, so the Intel one is still on the CPU. It is sufficient for the typical non-OC use and cores reach 75-80 during the IntelBurnTest. Removing the board again is such a pain that I probably would never do it unless there is a problem.
RAM is still expensive so I did not add any more. It is running at 2666, which is not a speed listed by Intel for the 6700K (DDR4-1866/2133).
The battery in the UPS died again so I purchased a new 1300VA (780W) UPS locally. The old UPS from 2008 or 2009 was only 700VA and a single battery type that would not run very long. I'll get a new battery for that and perhaps use it for something else or to split the load on other parts of the system.