Thank you, Bonzo_fan for your astute observations. Your mention of the unbelievable and unsurpassed chemistry between Bonzo and Jimmy is something I have been very much aware of too. Indeed, Jimmy has commented on this, marveling at Bonzo's understanding of his playing.
Your remarks about the quality of post 73 recordings, yes I agree some sound great, I was just saying you can't guarantee that was the actual sound.
I further fully agree about the cohesive chemistry Zeppelin possessed and this is what captured audiences and singled them out relative to other bands. The real point here is that to generate that cohesion requires exceptional musical ability.
Just a comment about Dazed and Confused live. It requires incredible musical and physical stamina to play at the high level required for 30 minutes on this song, where the focus is primarily on the guitarist. Also, just occurred to me, I remember listening to around 72 D&C and John McLaughlin live on, I think a track from Birds of Fire. I was very struck with the similarity of the solos. Now one would normally think of these two players as poles apart, but, again, I go back to Jimmy's training and absorption of all the sounds around him. I would add that McLaughlin is renowned as a very fast player, but, when the music required it, Jimmy could play very fast as well. Just to end by saying I was fascinated at the similarity of some of the musical passages.