The origin of the derogatory usage of Guido

Guido:

• is a slang term, often derogatory, for a working-class urban Italian American. The guido stereotype is multi-faceted.

• Originally, it was used as a demeaning term for Italian Americans in general. More recently, it has come to refer to Italian Americans who conduct themselves in an overtly macho manner.The time period in which it obtained the later meaning is not clear, but some sources date it to the 1970s or 1980s. The term is not currently used in Italy. (Wikipedia)

Is there a reason why, among different typical Italian names of early Italian immigrants, Guido became the one used to refer to Italian immigrants with a negative connotation?

Was "Guido", perhaps, associated with a specific person? or was, possibly, the unusual sound of the name that made it a common derogatory term?

Slang dictionary accounts of 'Guido'

Robert Chapman & Barbara Kipfer, Dictionary of American Slang, third edition (1995) has this:

Guido or guido n 1980s teenagers A gaudy macho type: Guido: ... a greasy, pimpy, open-shirted, hairy-chested, gold-chain-danglin' sleazoid—Sassy [magazine]/ It's not my fault I look like a Guido—Montel Williams TV show {the name of a character in the 1983 movie Risky Business}

IMDb.com confirms that a character named Guido, who appears to be a pimp, is indeed featured in the movie Risky Business.

Guido had already become a famous comedic Italian name in the 1970s through the efforts of Don Novello's character Father Guido Sarducci, described in his Wikipedia article as "a chain-smoking priest with tinted eyeglasses, [who] works in the United States as gossip columnist and rock critic for the Vatican newspaper L'Osservatore Romano (sometimes mentioned as The Vatican Enquirer, a take-off of the tabloid The National Enquirer)." However, there is no connection in behavior or character traits between Novello's Father Guido Sarducci and the Guido of Risky Business.

J.E. Lighter, Random House Historical Dictionary of American Slang (1994) has this:

guido n. {fr. Guido, an Italian male given name} (see 1991 quot.).—used disparagingly. Also (of women) guidette. [Cited examples:] 1989 Nat[ional] Lampoon (June) 91: Think of all those grubby-fingered guidos you had to wait on. 1989 in Harper's (Mar. 1990) 73: The "guidos" ... have sixty chains and hair spray in one hand and a mirror in the other." ... 1991 N.Y. Newsday (Mar. 22) 67: "Guidos" are guys who usually have brushes in their pockets, drive expensive American muscle cars, wear Bugle Boy jeans, like dancing...and are mostly Italian.

Early Google Books matches for 'Guido' and 'Guidos'

The earliest Google Books match that I could find is from Doug Lansky & Aaron Dorfman, How to Survive High School—with Minimal Brain Damage: The Unofficial High School Handbook (1987) [combined snippets]:

Guidos (gwee'doz) are guys who look like a cross between a pimp and someone left over from the disco era. They are often named Chainsaw, Slick, Rod, Babyface, and Tiny.

Guidos usually wear enough gold chains to compete with Mr. T. A typical Guido also wears button-down shirts open just far enough to expose his navel, his hairy chest, and the miniature Fort Knox hanging around his neck. ...

Guidos drive cars that were purchased for about $500 and that have since had $20,000 worth of body work done to enhance their appearance but still don't have a muffler. These guys can be found cruising the main drag of any city in an attempt to pick up women. They use come-ons like "Hey babe, what's shaking?" and "Oh baby, baby, baby, you turn me on." and "Wanna cruise?" (After hearing these romantic lines, how could any self-respecting woman resist?)

From Francis Ianni, The Search for Structure: A Report on American Youth Today (1989):

Everybody is known by his race in this [high] school. You're either black, Chinese, or Hispanic, and the rest of us get known by who we hang out with. I hang around mostly with other Italian guys and we get called "Guidos," which usually means that you come from Little Italy, but girls who go out with Guidos are called Guidos too, even if they aren't Italian. When the Italians won the world soccer championship, we put up a sign "Guidos are Number 1."

And from Abigail Thomas, "Sisters," in Columbia (1992) [combined snippets]:

ABIGAIL THOMAS Sisters Once again our mother is disabled by love. Carmine is back. Carmine, who came before Henry Gold and then vanished, has reappeared now, after Henry and towards the end of Gordon. Henry was a poet, Gordon burned his house down, and Carmine is a guido from Yonkers. Big white car, red upholstery. The usual bad boy. My mother likes the bad boys. It isn't seemly. Plus, she is old enough to be his mother.

So the stereotypical associations of Guido go back (in considerable detail) at least to 1987, four years after Risky Business, but Google Books doesn't provide any matches from earlier than 1987.

Conclusions

I think that Chapman & Kipfer got the etymology of Guido mostly right. In its pejorative sense, the term may have emerged from a combination of influences, probably not earlier than 1983—but the main ones likely were (1) as a distinctly ethnic (Italian) name (2) associated first with a comedic figure (Father Guido Sarducci) and (3) then with a flashy, vulgar, and dangerous stock character from a teen-friendly movie (Risky Business). And despite various semi-disclaimers that Guido isn't 100 percent associated with Italian Americans, it strikes me as being an ethnic stereotype/slur.