John P. Ryan appeared as another character in season four's Starksy and Hutch: Birds of a Feather (1977)
Frank Malone looks too young to pass as Rosey's father. In reality, John P. Ryan was only 16 or 17 years older than Tracy Brooks Swope.
In addition to PMG marrying a woman whose name was a homophone for "Rosie Malone", Glaser's first wife Elizabeth Glaser was a dead ringer for Tracy Brooks Swope, the actress playing Rosie. In fact, their faces are so similar they could have easily passed for sisters. Not only that, she shared the same name with his wife #2.
In this, Starsky falls deeply in love with Rosey Malone. In a very strange turn of events, Paul Michael Glaser would end up marrying a woman whose name eerily rhymes with "Rosey Malone", his second wife Tracy Barone. This often happens with actors (such as John Stamos and his fictitious Full House wife named "Rebecca", then later marrying a Rebecca (Rominj). This phenomenon is referred to as "Life imitates art"; it is a "subconscious choice" and many actors are prone to it. It is set in motion by the following equation: Emotion + Repetition = Manifestation. (Actors do a lot of rehearsing (repetition), add emotion to their words and this leads to the subconscious attraction and manifestation is the end result.)