IBM PC AT!
This was the second item that I set out to bring home on my vintage computer road trip. The classic 5170 complete with CGA monitor and Model F keyboard. It booted up just fine for my test run, and let me list the contents of the HDD. However, I couldn't seem to find a floppy disk that it liked, but I will deal with that another time.
Overall, this computer needs some serious care to bring it back to a state of being that I would consider to be acceptable. There is a considerable amount of dust and what I assume to be cat hair inside of the case. I may bring this thing to work and use the air compressor to give this thing a good blasting to get rid of years worth of particulate build-up. Plus, the case needs to have all the rust ground away and a fresh coat of paint.
As blasphemous as it sounds, I'm considering painting it a color other than the stock beige. But I can't paint it any time soon, nor will I worry about for now. I'll probably start with simple memory checksums for now, then maybe work up to memory stress tests to see what the seller was talking about. The hard drive is original, so I wouldn't be surprised if it gives up the ghost soon. Might not be a bad idea to start thinking about a suitable replacement.
I'm excited to really get into this one.