The b-side was recorded at a session, so it can be posted only if you post the whole session that contains that recording. But yeah, the rip from the single can't be posted.
I'm not really sure what it is, as I don't have the single. I received it from their official website (i believe?) a few years back. If you want I could PM the thing to you and you could see if its any different from the single. Or even better, I could just give you the length of the song.