Delaware County NY Genealogy and History Site

I need help identifying people in photo above. The caption on the picture was "Grandma Russell's mother Mary Merwin's birthday party" but no one in the group photo is identified. I'm 95% sure the lady in the middle in the light colored dress is my Great-Grandma Jennie (Flummer) Dewey, the young woman next to her is my Grandma Flora Dewey, and the white haired man with his hand on the young woman's shoulder is my Great-Grandpa Claud Dewey. The others are most likely Russells, Merwins and Flummers. I compared the young woman in this group photo "Flora", to her daughter's, Beverly Anderson's, graduation picture, and they definitely look related.

The good news is my cousin Terry (Stringer) Peck found a picture of our Grandma Flora Stringer in her mother's Bible. Flora was admitted to New York State hospital in Binghamton back in the late 40s for Huntington's Disease; the picture shows her in a wheelchair holding her 2 1/2 year old grand-daughter Gloria Stringer, in Dec 1955, so it was taken at the hospital. She looks like an older version of the young woman in the group picture I found on Ancestry.com

1909 MARRIAGE
Name: Jennie May Flummer
Gender: Female
Age: 18
Birth Date: abt 1891
Marriage Date: 20 Mar 1909
Marriage Place: Delaware, NY
Father: John Flummer
Mother: Carrie May Mervin
Spouse: Claude C. Dewey

1920 US CENSUS - Masonville
Claud Dewey
Age: 31
Birth Year: abt 1889
Home in 1920: Masonville, Delaware, NY
Street: Parker Hollow
House Number: Farm
Marital Status: Married
Spouse's Name: Jennie Dewey
Household Members:
Name Age
Claud Dewey 31
Jennie Dewey 29
Flora Dewey 10

1940 US CENSUS - Masonville
Name: Leland Stringer
Age: 35
Estimated birth year: abt 1905
Home in 1940: Masonville, Delaware, NY
Household Members:
Leland Stringer 35
Flora Stringer 30
Douglas Stringer 11
Ivan Stringer 10
Robert Stringer 7
Harlan Stringer 6
Jean Stringer 4