This HP P1100 is a rebrand of the Sony GDM-500PS 21in Monitor. Here are the specs for the monitor:
https://crtdatabase.com/crts/sony/sony-gdm-500ps
The shell itself is in very very very good condition, barely any damage, will clean up even more, looks like barely any yellowing. Really great shape!
It boots up and all the buttons work. However, there is one major flaw. The screen is displaying in a very wavy fashion, as shown in the photos. A specific capacitor on the PSU I believe is to blame. These things are not particularly hard to work on, and totally worth saving. I will eventually get around to fixing this issue, and then subsequently increasing the price.
This thing will be an absolute monster once it's recapped. Only reason I'm getting rid of it is because I will be moving into a MUCH smaller space, and I will be unsure if I can use it with my main setup. However, I am in no rush to get rid of it by any means.