The Helen Scheyner album says nothing about those who helped her on it, but Helen's daughter who was also on the album lives in the DC area, and 'might' know something. If I can contact her, I'll post something. Ed Trickett and Gordon Bok also sang on a couple of tracks, but it's not clear who knew whom or when tracks were recorded.
(I assume Genny also lived here at one time...but, it's an old album....)