William George & Margaret Ella (Leighton) Collins.
I walked the entire cemetery; and they were solo on their lot (no other direct descendents alongside them--or elsewhere indicated that I could locate).
I believe you'd previously indicated that Margaret's parent's were: Herbert N. Leighton & Velma Kossuth McKenzie?
Does this sound right: Herbert N. Leighton; b. 5-2-1851 in Harrington, ME, d. 6-19-1934?
It would seem more straightforward for Jim to work his way backwards, via the Maine State Archives & vital records (Leighton is a common surname there).
Town of Bar Harbor would have their certified copy of marriage, for instance.http://www.barharbormaine.gov/depts/
Sally Robbins, Town Clerk of Harrington (more boundaries & dates issues--Addison might pop up for Velma, for instance--Edmunds was/is an unorganized township)!
Velma Kossuth McKenzie married Herbert N. Leighton on 15, Nov., 1879 (Harrington); Velma b. 02 JUN 1851 (Addison).http://www.maine.gov/local/washington/harrington/
As noted previously, check w/Lois Crabtree Johnson fmi occupations & general late 19th & 20th century data (if you haven't already) for Hancock.
Otherwise, try Washington County's town clerks--looks as if Margaret's birth family of Leighton-McKenzie would be noteworthy, as would William's Verona-Caribou Bridges surname adoption).http://www.maine.gov/local/washington/
These are large hi-res shots. Simply right click & save however you wish (you can edit per your own preferences, thereafter).http://i57.photobucket.com/albums/g211/mainefem/Personal%20P...http://i57.photobucket.com/albums/g211/mainefem/Personal%20P...http://i57.photobucket.com/albums/g211/mainefem/Personal%20P...
Drive into Riverside Cemetery's entrance (turn hard right on your wheel--roads/aisles are narrow!), take first right (over two rows, then straight down that aisle--about 3/4 down, nearer the bottom of that hill's incline, closer to Taunton Bay--on your right).
Hope this was helpful, Gloria!
Sorry so tardy in uploading the photos for you & Jim....