Nothing crazy, just a list of interactable items that can be found in your section of the Town Hall after hitting certain milestones. Each one gives a small amount of narration or lore. Feel free to fill in the gaps i might have missed
Mil Helmet - Finish The Beast Within quest (?).
Record Player - Finish the Dead Beats (or Good Vibrations?) questline.
Valve Wrench - Finish Power Gambit quest.
Keycard - Finish the School's Out quest for the Exiles.
Toy Elephant - Finish the Hydro-Puzzle quest and talk to the family back in the Town Hall.
Baseball Bat - Finish the Bait and the Beast quest.
Trophy - Finish the The Fast and Fortunate quest line.
Map with Photos - Updates after each "Boss", each photo is interactable.
Not sure if Kyle Crane's Recipe book shows up at some point but i noticed it.