Searching for long lost cousins who's names and last known residences were:
Diana Leff (Crow Wing, MN)
Robert Leff Jr (Crow Wing, MN)
Linda Leff Engholm (Alameda, CA)
They would be about 60 years olds now.
Deceased grandparents were from Lewis Cohn and Anna Chinka Balaban, both born in Russia and presumably died in MN.