Thanks for your long, detailed and very interesting piece, Andy. Although I'm not a musician, I get the general idea. By careful listening and analysing note by note if necessary and coming to the conclusion that what we are listening to is not Bix, because, as you point out, his ear never suffered, not even when he was in poor shape, so the chances are it could possibly be by another musician. This is something a trained musician might normally pick up on. One of my regrets is not learning to read music when I had the opportunity to do so when I was a kid.
Secrest made his living playing "Bix Style" cornet and was an invaluable member of Whiteman's brass section once Bix's bad habits had begun to affect his playing. From 'Bugles' comes this paragraph on Secrest joining Whiteman:
"Whereas twelve months earlier a comparison of the two musicians would have been disastrous for Secrest, the now dimming lustre of Bix had the effect of magnifying his emulator".
I have heard a clip from a 1941 Connie Boswell record on which, there he is, playing into a derby, still doing his "Bix" party piece.
Andy, thanks for taking the time to post your contribution and thoughts on the current subject under discussion. And finally, your various video clips with your band on the Internet are much appreciated and enjoyed by viewers and fans over in Europe and I expect elsewhere too. Thanks to dedicated musicians as yourselves, Bix's name and music lives on.