During The Impossible Past sessions, the band had some acoustic demos recorded that later on became songs for the actual album. These songs were released on a cassette at first but are now available on vinyl too. The Menzingers called these demos On The Possible Past.
I can easily say that Casey is my favorite track on both the Impossible and the Possible Pasts. But all songs deserve a listen, especially the final album versions. If you still haven't checked The Menzingers, please do, they are the band that members from Bad Religion and Pennywise would recommend you to listen to!