My great-uncle Samuel SCHWARTZ died in 1954, while married to his second wife, Margaret (his first wife, Anna, had died in 1940). According to family lore, Sam and Margaret drifted away from the family after their marriage and once Sam died, leaving nothing to the children of his first marriage, the rift was complete.
Now for the mystery: The next of kin listed on Margaret's cemetery info is "William Schwartz, son." Although I don't know whether this is the correct Margaret (I've guessed wrong before!), nobody has ever heard of Margaret and Sam having a son. Is William Schwartz a distant relative? Does he still have any of Sam Schwartz's family heirlooms?
Mystery partially solved! My cousin Bonnie just told me she remembers that Margaret had a child from her first marriage, so William must have been my great-uncle Sam's stepson. Where William might be and what he knows about the Schwartz family remains a mystery still.