Maybe sliding the panels a little without dismantling tons of stuff would help
As stevelup said ...
If it's 1 row or dual row is a good start
Normally you have 14 (without backlight) or 16 pins header (with backlight)
You can search HD44780 lcd's, you will have tons of pinouts available, the only thing left is the contrast adjustment pinout to decipher, maybe an trimpot, an fixed resistor, or simply an short between the pins ?