To offer a second opinion, the Cray-1 was the only thing I found cool about the Computer History Museum in Mountain View. It was otherwise just a like a big website, the history was all dead. In contrast the National Museum of Computing next to Bletchley Had lots of computers turned on, with enthusiast volunteers demonstrating and explaining things. You could punch paper tape and feed it to the Dekatron and see the memory changing as the program ran, or poke at magnetic core memory sheets and someone was right there to discuss all the old tech.
I do miss the old "visible storage" Computer History Museum - where you could walk around and peek into so many great machines. The current version has been musee-ified to death. It might safer from flocks of school kids but a real shame for the rest of us.
They have very strict policies around powering up their devices. I tried to persuade them to look into the original IBM 2260 terminal font design (it is implemented as core memory with missing cores for bits and it resided in the terminal controller). Of course they said no.
My mind was absolutely blown by mercury delay line memory of the UNIVAC 1. The things we did before silicon dynamic memory were works of crazy engineering.
Is this a Williams tube or a Mellon tube? I have seen ONE or these, and they used to be more numerous than pocket change, at least the ones that no longer worked. Unused they were treated like fine crystal, used like empty beer bottles.
I wanted to hook one up in a tv to see a 1" movie, or maybe a 3/4" movie with the aspect ratio but the refresh rate was really slow, so it was useful as a memory.
You might also like the National Cryptologic Museum next to NSA's HQ. The Cray they have isn't as interactive, although you can sit on it for the Sneakers vibes. They have multiple Enigma machines you can play with which I thought was pretty fun