The Wrecking Crew is a great documentary, for many reasons. I don't remember Leon being interviewed, but he was surely mentioned.
The New York Times obit gives a good overview of Mr. Russell's amazing career; they call him a musician's musician. I love the anecdote that over 100 artists have covered "A Song for You" but it took Mr. Russell just about 10 minutes to write it
http://www.nytimes.com/2016/11/14/ar...t-74.html?_r=0
IMO, Karen Carpenter did the most moving rendition of "A Song for You." Particularly when she gets to the lyric: I love you in a place where there's no space or time/I love you all my life, you are a friend of mine...
https://www.youtube.com/watch?v=CQKnpJul8MU
I gotta stop now, I'm verklempft. Talk amongst yourselves...