Over the weekend, I engaged in a bit of research regarding two photos showing a PDP-1 next to a model railway layout, commonly known as "The PDP-1 at Tech Model Railroad Club, MIT". (Spoiler alert: This is not what these photos are showing.)
(One of the two photos in question, Computer History Museum, Catalog No. 102649722.)
The story consists of two blog posts, the first one is on the photos themselves and what they might be actually showing (this was subsequently solved with the help of the Hacker News community):
The other one is about the very machine seen on these photos (and also a bit about PDP-1 lineage):
Any further information on this is welcome!