You can always find something at Jinxed. They have a wide assortment of uncommon objects from crocodile skulls to hymnals from the 1800's, old photos, bottles, tools, typewriters ... anything you can think of.
If you're unable to make it to one of their four locations they do sell online. Make sure to keep an eye on their Instagram, where they also post new items frequently.
Philly Fav's: Standard Tap
Philly Favs: Graffiti Pier
Philly Favs: Greensgrow
Learning Latte Art at La Colombe