Brilliant job, from my POV, on three levels Michael.
First, you've tackled both Stephen's and Neil's guitar parts, and done a great job on both.
Second, the lead vocal is superb - the timbre of your voice, to me, is a bit more like David than Stephen, but well done.
Third, the harmonies are lovely. Croz always reckoned that he had the hard, "middle" part. It wasn't 'til the a capella section that I caught it from you. Of course, the "middle" harmony is not necessarily the one between the high and low parts, but rather the third between the root and fifth, and you've put that part lower than the others beautifully.
I'm not surprised that you didn't (or did you?) try the Graham Nash part - I'd say that is too high even for him these days.
***** from me.