Thanks so much for your reply and good information. I will contact Lois Johnson. My stepson Jim is a novice to genealogy but really wants to learn more about his mother's family--the Collins and Leightons-- and see his grandparent's graves in Riverside Cemetery when we visit Maine next summer so I'm doing some preliminary work for him chasing through census records, etc. Jim's mother who is the Collins-Leighton descendent has been very helpful but really doesn't know much about her family but is quite interested. My husband, Jim's father, passed away several years ago but had taken me on two wonderful trips to Maine and both times we stopped at Riverside to pay his respects to his former in-laws.
I have not done any Maine research in many years and it is a refreshing break from trying to sort out my own Pennsylvania Dutch ancestors! Thanks so much for your help.