Thought I'd provide the outcome to this situation with the fuel gauge. I'd had a feeling that someone had been into the IP cluster at some point, so I pulled the IP and removed the cover over the gauges. I then rotated the fuel gauge needle counter clockwise until it was pointing towards "E" again. Much to my delight and surprise the gauge worked as it should.
Judging by the amount of dust on the cluster, I'd say it was several years since anyone had removed it, if it ever was removed. There weren't any signs that the cluster had ever been removed, so...I have no idea of how, or why the gauge needle when past the full mark, but apparently once it had, it couldn't return.
Just another one of those strange problems found in the world of automobile repair.
Thanks for the tips guys, and I hope this information might be of help if someone runs into a similar problem.