In the mid-17th century, dick became slang for a man as a sexual partner.[5] For example, in the 1665 satireThe English Rogue by Richard Head, a "dick" procured to impregnate a character that is having difficulty conceiving:
The next Dick I pickt up for her was a man of a colour as contrary to the former, as light is to darkness, being swarthy; whose hair was as black as a sloe; middle statur'd, well set, both strong and active, a man so universally tryed, and so fruitfully successful, that there was hardly any female within ten miles gotten with child in hugger-mugger, but he was more than suspected to be Father of all the legitimate. Yet this too, proved an ineffectual Operator.[6]
An 1869 slang dictionary offered definitions of dickincluding "a riding whip" and an abbreviation of dictionary, also noting that in the North Country, it was used as a verb to indicate that a policeman was eyeing the subject.[7] The term came to be associated with the penis through usage by men in the military around the 1880s.[1]
Just pointing out that Yiddish has several dozen words for types of dick, used to describe men's personality or status. Like Schmuck. I'm told Yiddish has zero words for Vagina, out of respect.
Penis is derived from the Latin for "tail". As penis came to mean schlong over time, Latin switched to cauda. Dick only became a euphemism for the fuckstick in the 1980s. Why? I have no idea. But other proper names are/have been used including "Peter", "Johnson", and "John Thomas" that I can think of off the top of my head.
It would be awesome if you or someone could provide a link towards a relevant article backing what you said. But hey, your words sound loosely legitimate.. 👍