I was going to write last night but it was just too late for me.
Looks like you had great fun with this. You are both great players and I enjoyed what you were doing.
Is Blues your normal thing? I just got the impression that maybe your regular music might be different. Don't know why. You were both quite 'busy' on guitar and I wondered if this was your normal style of music.
As for the singing, well you said it is early days. I thought you made a good job of it. Both of you. The vocals didn't come through soo well, but thats guitarists for you........not always there first priority.....the vocals ist it? 
What made me check out your post was that I performed this as well live on Saturday - unplugged, so it was a fresh theme for me. Its a great song I've always liked it. My favourite version is Claptons live from 'EC Was Here'.
Thanks for sharing the vid.
No Hits, No Hype.......................Classic Rock Jan 2012