The "mold/fungus" on the D3/D300 inner display was not exactly that and probable cause was the mounting tape, underneath. (On my old D300 it also looks like they wiped off the underside glass with a damp finger.)
When powered off, it looks cloudy around the edges. When used for chimping the bugger is fine.
Do your homework. Applying a glass protector is a good idea to keep it looking new. Removing ANY protector from a plastic touch screen, I've found can pull off the non-glare coating, pretty much ruining what you intended to fix.