Some observations:
I've read Delauney's book a number of times. As Brownie suggests, it is more of a memoir than a history of Django. A number of interviews with Stephane Grappelli, were at odd's with Delauney, concerning the war years. Records of concerts in England after Django supposedly returned to France, etc.
I found 'D's' version of the 'escape' to Switzerland, sadly, very funny! If you are interested in the subject, I would research Grappelli interviews. It's definitely another point of view. Delauney's book is worth reading for the 'Keystone Cops' quality, of aspects of Django's quirky personality. The photo's alone, are worth the price of the book!
I look forward to a comprehensive review of the new biography.
pmf