Yep, sounds like you have the now obsolete 8EP 395 G3,chances of finding new lid or indeed a used one are slim to say the least.
I've had a look through my old gear and if you had of said "8EP 396" then you would of been in luck,sorry that won't fit because it's for the compact or you could of had it.'
Think you will have to change the panel for a G4 unfortunately,unless one of the lads on here have one kicking around.I used to use Hunters years ago for replacement bits and bobs untill obsolete parts became unavailable even to them.
Look on the brightside it gives you a good reason to upgrade.
Have a look at the scantronic 9651 :)
e manno, October 2013