If you delete an item in Zotero, it would be in the library's trash, and you can restore it from there. Once something is removed from the trash, the associated file is removed from the 'storage' folder. So if you still see something in 'storage', it should still be in your library.
You can paste the 8-character folder name into the Zotero search bar in All Fields & Tags mode in both the library root and the trash to try to find the item.
Upgrade Storage
You can paste the 8-character folder name into the Zotero search bar in All Fields & Tags mode in both the library root and the trash to try to find the item.