Display in bad state on stored 48G

[schuh]

Hi all!

It has been about 20 years since I purchased my 48G.
I did upgrade to 128KB, plus 128KB+512KB of internal memory (poor work on the keyboard plate surface, I know it's ugly, but works!).

Yesterday my wife asked for a handheld calculator, then I offered my 48G.
It was stored in the original soft case.
Inside the case there was a small silica gel pack, and a couple of cardboards inside the internal pocket, to add extra protection for the display.
The case was inside a drawer in a wooden TV rack.
So, I thought it was pretty safe, and I just needed to install the batteries and turn it on, but as soon as I took it out of the case I realized I had a problem.

The display is in a very very bad state, which is weird. It looks like some sugar concentrated liquid was poured over and dried. The surface is rough.
Anyway I tested it, and it beeped, and the display seems to work, but the central area is barely readable (see attached pics).

Later yesterday I figured out what could have caused that.
The spot where the calculator was is exactly below the PS3 in the rack, and the console used to be powered on for several hours eventually, getting hot.
So, I suspect it's heat damage on the anti-glare surface of the display, which I suppose it's some plastic material, which melted by the continous heating, although probably not too high temperatures.
I still have to test playing some graphics intensive game to confirm what is the temperatures range it gets inside the drawer.

Anyone already saw something like that?
Any ideas on how to fix it, or at least improve display surface?
Maybe I'll have to replace the display, which seems to be a hard to find part.
I have seen old 48G/S/X on sale, but either they're functional or have damaged display (some seems to have the same display problem), not so useful for my needs.

Thanks for any help!

Cheers,
Saulo