My name is Cathie Ellison, formerly Reeves, and I know 3 of the people in your group photo titled Pool's Paradise 1968. On the couch, right in the middle in the dark dress is my mother, Joan Reeves and to her left is Patsy Geary. In the back row, right behind my mother in the white top and plaid, is my eldest sister, Linda Ellison (Reeves). I also recognize the young blonde girl on the far right but her name escapes me right now. Perhaps a Highfield? The pic is too small to really see the faces, even at the largest setting. Sorry I couldn't be more help.
FYI. My older sister Judy Monk was also involved with the Park Players, as a prompter and I was in 3 or 4 plays myself in the early 70'slong with my sister Linda. My Mum had quit by then but my other sister Judy was still the prompter. Guess you could say it was a "Family Affair".