Pat and I. (sorry couldn't resist that
The Kentucky Muse (Mary Ann Currier) was a featured PBS artist.
You can click on the link at the bottom of my post, in my signature line for the Oil Pastel Society. You can go from my page into the society menu and look up the professional members and distinguished members. I'm not sure how many are nationally prominient but they are well known in pastel circles and some such as Bill Cheevy are well known in New York circles.
Hundreds of years ago many artists made their own oil pastels to use on field trips but kept their formulas secret. (Years ago I also did some research on the subject but no names come immediately to mind)
I modern times Picasso approached Sennelier and asked them to create a professional grade of oil pastels for him. The Japanese had a student grade of oil pastels for many years prior to this time.
Good luck on your research. We in the oil pastel forum would be interested in reading your report. Let us know if you post it to an electronic media when finished.