I'm pretty sure that Studio Music have it although it's not on their web site. Try contacting them http://www.studio-music.co.uk/acatalog/Contact_Us_Pages.html
Just in case you don't know, the first ever recording of this song featured Bix Beiderbecke on cornet. It was one of his last recordings: http://www.youtube.com/watch?v=1NELdNYiKCU
If you are not after a particular version I have access to the copyright and can create a new arrangement for you if required. andy@pdfbrass.com
http://www.justmusicuk.com/spweb/details.php?catno=JM35562 - Alan Morrison arrangement - pretty good to say the least!
I arranged it for an audition a few years back (from the band score) but seem to have misplaced it... will let you know if I find it!