Headscratchers / The Simpsons S14 E6 "The Great Louse Detective"

• Exactly how old would Frank Grimes Sr. have been when his son was conceived? If we assume the present day of "Homer's Enemy" was the same as its airdate (1997), that would make a 1962-born Grimey around 35 when he died, and Grimes Jr. doesn't look much younger.