I do know the history of the thing. It was purchased alongside the workstation that now sits in my shed in 1989 and saw weekly use for about six or seven years before it was slowly pushed further into a storage room and I collected everything in 2004 (and it was doing it even then). The tube looks like it's seen a lot of hours. Contrast is poor and the corners have focus and convergence issues. Tried to put the HV probe on it this morning to see if the HV was sagging after a period of time but my portable fluke has decided to stop playing nice it seems.
I did inspect the boards for iffy resistors but they all seemed fine. The monitor actually has a fan in it so the ventilation is a lot better than most 21" monitors I've seen.