Edit: Actually, looking at it again, it seems like the mask just could be warped. It's difficult to tell without an actual image on screen, the black space could be hiding it. Can you snap a shot of it with an image filling the screen?
After taking another look I noticed that the image is blurred & slightly discolored across the entire top of the screen but the rest of the screen seems clear. There also seems to be a couple light horizontal lines going across the screen when viewing a lighter color background like the photo below.
Could a degaussing coil fix this problem or is it an underlying issue?
I couldn't get a good clear picture of the screen with a full image. Any suggestions to get a good picture with a camera?
Just tackle the convergence problem, and then see if you can live with how the image looks overall. I continued to use my PVM for years, and if it ever really bothered me I tried to size the image way from the warped area of the screen.
It's also what started me down a path of hoarding various CRTs as I looked for replacements.