|Death Certificate of Mary King O'Hara. 5 November 1949. New York City Department of Health and Mental Hygiene.|
Which is why it really gums up the works when the grandparents he names are not the ones I expected.
One piece of information, though, makes me wonder whether John was a truly reliable source, or whether he might instead have been confusing dates. Or was it that he had an excellent reason to get them right? Mary's date of birth is given as 3 December 1875. Her husband, also named John, had died 3 years earlier on 3 December 1946. Did John Jr. provide a date that was familiar for the wrong reason, giving his father's date of death rather than his mother's date of birth? Or was it a date he was sure to get right, forever in his mind after having lost his father on his mother's birthday just a few years ago?
Beyond the issue of her parents' names, the only slightly surprising piece of information on here is Mary's middle name, which I hadn't known, although she was routinely "Mary E." on records.