There are one or two overblows - I remember hearing and noting them. It's been awhile since I lsitened to them, so I can't say at this point where they occurerd, but it seems to me he was playing in 12th position at the time. There were two cassette albums with Don Les and Mo Vint, by the way.
I had extensive conversations with Don Les in the early 1990s and he confirmed that he did use overblows. He told me the story, which someone else has already mentioned, of having been taking a midday nap between shows and being awakened by a visitor - a young man - who played him a complete chromatic scale with overblows. After this Don went back to sleep and couldn't remember the young man's name. Did he dream the whole thing? Who knows?
Winslow