Carms there already is a film about Rodd Keith, or rather, he's mentioned in it big time and his son does a lot of interview stuff - "Off The Charts - The Song Poem Story" - I have it on dvd, or I did have, I might have chucked it last time I had a clear out. It was a one hour documentary film shown on US tv.
I used to have a site bookmarked which had sound samples of 90% of all the records released on Preview.
The movie is on YouTube as well:
https://www.youtube.com/watch?v=KOqn-I5u1MY&wide=1
Preview sure was an "interesting" label!