In the fall of 2015, on a dull grey Sunday morning in Block-H of Bletchley Park, I was afforded a great honor. Part of the WITCH-E project is to document as many aspects of the Harwell WITCH as possible, and one of the things I found absolutely no information on was how the wiring on the back side of the WITCH was handled. On this particular Sunday morning, prior to the National Museum of Computing opening to the public, I was allowed to take detailed pictures of the back side of the WITCH. Using this information along with the original schematics, I've replicated the "Interconnects" in generic fashion for the WITCH-E. Here are some of the photos of the original WITCH:

NOTE: Pictures are used with the permission of the National Museum of Computing for Non-Commercial purposes: Creative Commons CC-BY-NC 4.0