Richard Chamberlin was interviewed extensively for the film, and here's hoping that Dianna's editors didn't cut too much. I hope she had total control to prevent that.
I think most people at this point would really want to hear the fascinating untold histories behind the machines from the original people like Richard, John Bradley, Dave Biro or Geoff Unwin - people who were at least around in the golden age as this info is much more 'underground' (and much more interesting - based on the conversations I've had with them. I hope they each divulged at least most of what I was told.)
This film can potentially fill an existing void most people aren't aware of.
The last thing the world needs are more "Johnny come lately musicians" espousing about how they use the mellotron or chamberlin sounds, or how great their band is because of it, or especially - how unique their samples are. I truly hope those tedious and painfully boring interviews are kept to a minimum, and that all the interesting history is finally told. Things have been out of balance in that area for way too long.
And sorry but Kanye West's name has no place even being mentioned in THIS film. Jon Brion's worked with much better than him. That guy's about as worthy of attention as a dead cat attempting to decompose in outer space.