All I know is two things...
1. The "ring" is from an old gate
2. There is no official storyline.
Anyone who wants to disagree, go ahead but I am 100% sure on those two facts.
I agree with you about the "ring," but I disagree a bit on point #2. Disney's Imagineers don't just design an attraction--even simple things like the TTA have storylines. These storylines help to keep the Imagineers consistent throughout the scenes of each attraction as well as consistent within each land and park. I'm not saying that the official storyline is the same storyline that fans have developed over time, but I'm sure the Imagineers used a storyline when creating the Haunted Mansion.