You were right! Opening the breech I did find an oval with the letters E L G. Below the oval was a capital T topped with a crown, star, or fleur-de-lis (I can't quite tell which, it's pretty small).
I also noticed that there was a very faint "AS" on one side of the barrel. The serial number on the opposite side is 4892.
There is some nice engraving around the trigger area (which can be seen in the photo) and on the metal butt of the rifle. The wooden stock has some cross hatch like engraving on it (I assume to provide a better grip).