DoomBuggies wrote:
I know a quite few years back (at least a couple years before WDW's latest renovation), WDW was trying to find some wallpaper to allegedly redo the corridor wallpaper. They even contacted DoomBuggies for help with the design. It was interesting - I was surprised that WDI wasn't involved, but the project didn't move forward much at that point in time, so I suspect it was either a rogue park initiative, or perhaps that they were considering using the wallpaper for something else entirely, such as a retail display.

At least Disney finally got to use the wallpaper design I'd developed for the packaging of the latest release of the Haunted Mansion 40th soundtrack (and the 12" box set as well), so it didn't go to waste.
I hope they paid you a little something for your trouble.  You should have woven your name into the design in some sneaky way.

As for the stain, it just looks a lot like what I used to get on the walls and ceiling around the vent of our ancient (and now gone) furnace, except that the HM stain is more extreme.  I suspected that a heating vent may have once been in the wall over the clock-hall entrance and that they had allowed the filter to get much too dirty (or it didn't have a filter).  It doesn't look like a splash stain or a spray-paint mishap to me.  Who knows.