I know that this is a really old thread, but I saw a video today that answers many of these questions on Mingus. It's long...but in the first part (in the studio) you see many close ups of Mingus playing what would today be considered high action, and gut on top wound on bottom. The best shots are further into "Meditations On Integration" when he picks up the bow in the more rubato part. Stay with it. It's great stuff, especially on headphones.
https://www.youtube.com/watch?v=2phw7eXrmCM#t=677