Thanks for the Tower/SEA info! Do you happen to have pictures of the SEA easter eggs in the Hollywood Tower Hotel? Also yeah you're right about the mummy being the most egregious, other SEA members went plundering too but this dude was stealing whole entire people
The most recent, actually-confirmed-by-CMs, actually-in-the-ride reference is this monkey by the photo counter in Florida. It's supposed to be the Mystic Manor monkey, and was added in 2024 (after my most recent visit in 2023), so the photo is by @chunkecheeks
As for other SEA references,
This now-removed newspaper prop contains what I'm fairly certain is a canceled SEA character, Pete Corrigan, manager of the Hollywood Tower. The article muddies the waters on what version of the Hollywood Tower is canon, as the photo shows DCA (and this newspaper was in California Adventure) but the detail about mahjong at the hotel is Florida-exclusive. It also gets other points of lore, like the hotel's opening date, wrong. The transcript of the article (since the photo isn't the easiest to read) is in my post here: https://a-land-of-shadow-and-substance.blogspot.com/2018/03/the-tower-and-buena-vista-street-hidden.html This newspaper was in place until 2018, when I took these pictures. It disappeared about two weeks later.
Then, there's this photo from Shanghai Disneyland (which I haven't personally been to), taken by @laffiteslanding
The main headline and photo clearly shows/references the Temple of the Crystal Skull from DisneySea, although it oddly calls the group the League of Adventurers/LoA rather than the Society of Explorers and Adventurers/SEA. HOWEVER, as can be seen at the left, it has an article about the Hollywood Tower Hotel incident! So Hollywood Tower = same universe as Temple of the Crystal Skull, which is in-ride observably in the same universe as Hotel Hightower! Also interesting is, based on what's readable of the Hollywood Tower article, we have another new set of Tower OCs in play: the elite Herman family, who seem to be the Elevator Five, completely overriding the TV movie names and relationships for those characters as well.
And while we're on the subject of SEA... are there any confirmed Pirates of the Caribbean characters in there? Another pet theory of mine, ever since Curse of the Black Pearl, is that the Pirates movies take place in the same universe as Indiana Jones.