I have a case for a Mac Plus, and I figured I would put a mini-itx board in it... So I need a screen that will fit it.
No, but if you find one, let me know. I'm in the same situation with a Classic II case and an SE case.
Try searching for an 8.4" screen on ebay - there are sellers from Hong Kong and mainland China listing them every week.
in my searches i have found a pretty close solution, Ipad gen 3/4 screen and converter board, both can be had for around 100 or less online
the screen is pretty close to the cut out for the SE, Classic and 512/plus, might be some overscan adjustment needed to make it look good