I'm back and I heard you guys talking about me. The shadow knows.
On ITT 512 KSU's, there was a small fuse panel mounted to the left of the power supply on the mounting rails. It utilized flat fuses. I don't believe that any other manufacturer did this, except possibly Stromberg-Carlson, so I am pretty sure it's an ITT.
Now as for that thing to the left of the KSU itself, your guess is as good as mine!
