Note this is not Dylan choosing to sing it again because the piano playing and the singing are identical. I guess this was done because the cut had made the song much shorter but in reality it is pretty pointless. Bells has much less hiss. Stereo channels are probably switched. Might be a rough mix, I can't tell.
Bells has significantly less hiss than Deeds.
Some telling lyric differences confirm this. Bells has slightly less hiss. Bells has less hiss. Stereo channels switched. Bells is in significantly better quality than Deeds due to reduced hiss.