[quirksilver]

I'm afraid this is a rather late reply, but just in case you still wanted something, would this be of any use?

http://classicsax.com/asi/smrglaz.pdf

It's by no means a full manuscript, but it does have a few excerpts of Glazunov's original autograph, and commentary by Rascher. I came across it while I was researching for my essay on the Glazunov.