Although I'm very interested in this computer story, I must admit that at first I thought this referred to a poltergeist story I heard about as a youth [1].
I didn't know this, the title had just the right tune to it. – But it's a delightful pun, anyway, since these photos seem to haunt me like some poltergeist activity within computer history.
This is absolutely delightful. What a great hobby - tracking the historic locations of different PDP minicomputers through analyzing archive photos.