..for your thoughtful response. When time permitted today I found quite a lot of information online, too.
Regarding your question about Bix's counsel, The Davenport Album seems to hint that it could've possibly been prominent lawyer C.H. Murphy - one of the men Ivens stated that he consulted about his daughter in his "affidavit." The book states - "More likely Murphy's involvement was as legal counsel for Bix. The Beiderbecke family would have hired a lawyer when their son was arrested. He would have been there for the bond hearing. And in preparation for the case, he would have talked to the arresting officers, and deposed witnesses."
(forgive me if you were already aware of this section in the book)
I am grateful for all the information and hard work that went into making The Davenport Album.