If it's numbered "GE20" then that is an original LG drive and enclosure. It should have a "super multi" logo on the top of the case. It that is the one, the drive is a full size 5.25", and I'm pretty sure it has a SATA I interface.
The original LG branded enclosure can easily be re-used for a different drive of the same size, but it won't be pretty as the custom faceplate is part of the original LG drive.
Remove the four rubber feet from the bottom (they pop on and off very easily using ingenious friction catches) to reveal the four mounting screws.
There is an additional screw for the RF shield in the back, at the top edge of the rear.