The CD booklet says Oklahoma Film Orchestra. And one of the recording locations is Purcell, Oklahoma. I also thought that was interesting / random.
I looked at the credits of the PBS special. It says Kenneth Rice is the 'orchestra contractor', and no orchestra group is listed. So I think the live orchestra was contracted out to individuals or small groups (e.g. chamber orchestras). I think this is Kenneth Rice:
https://www.cyberstrings.com/bioSo, yeah. I think two sets of musicians.