Other thread doesn't have any replies yet, so I guess this one will be the official one by default.
Well, i am certainly jealous of your attic. definitely do not throw that away! It is certainly of value to somebody. these days, old computers with blinkenlights and toggle switches are quite valued by collectors. I'd love to have a machine like that one, though I've been buying too much stuff lately to consider buying yours. So, I'll just drool on my keyboard instead.
The picture shows the front panel of a PDP-11/45, a 16-bit minicomputer made by Digital Equipment Corp. Presumably, the rest of the computer is behind it. Assuming it's complete, that cabinet would just contain the CPU, memory, and interface cards. In that era, there would be no internal storage (i.e., disk drives). Storage would be via some combination of external hard drives, paper tape punch/readers, etc. All of those beautiful front panel switches and lights let the operator monitor the state of the CPU and toggle in code and data, bit by bit.
Is there anything behind that panel, or is it just a front panel? Even a front panel will interest people. Please feel free to share more pictures of it, so we can help you figure out just what you have. There are a number of folks here who should be able to figure out how complete the innards are based on pictures, and perhaps answers to some specific questions.
If it's a complete cabinet, rather than just a removed front panel, then it would be best if you could find a nearby buyer. A machine like that is heavy and fragile, and it could easily be destroyed in shipping if it is not packed just right. It would help if you told us where you are located.
Congratulations on your find! I wonder what else might be lurking in your attic?