Files larger than 63kb are your saved files. I have 3 vaults of different sizes, which explains different file sizes.
C: Users YOUR_USERNAME_HERE AppData Local Packages BethesdaSoftworks.FalloutShelter_3275kfvn8vcwc SystemAppData wgs LONG_ENCRYPTED_CODE ANOTHER_LONG_ENCRYPTED_CODE your saved here
If you do not see hidden files, go to the "View" tab in Explorer and select "Hide Projects"
If you can't enter the package folder, …