i love your cover and it sounds like the others i have found online. I just cant help but think that one of the strings is still tuned differently or something, when you listen to the recording it sounds like... i dont know the song seems 'brighter' than the Db open tuning that most people use. I agree with the Db for the first string, you can hear him hit it in the song. And the B + E strings sound accurate at Db and F...
Maybe its just the way it was recorded, and the guitar he was using couldve altered sound. I find the covers deeper and a little more bassy than the guitar in the song. Makes me uneasy because i wish i could get a slightly closer sound. But it is pretty dam close.