What this thread is missing is irony.
The guy portrayed in ‘Hey Nineteen’ is a middle-aged alcoholic and drug addict loser. Mostly all characters in Steely Dan’s songs are. The Nineteen is probably a high-school dropout skank that he is plying with liquor.
The Rino, or heavy Demo-Donor yacht class wouldn’t let him or his date within five miles of their club.
If they play this on yachts, then they probably aren’t even listening to the lyrics.
Note: many of those people own yachts. See: Using up the inheritance quickly.
Anyway, here's my take on the lyrics. The guy talks about being the "dandy of Gamma Chi" which is probably a sorority at a Ivy League college up in Massachusetts where he gets his "Sweet things from Boston...so young and willing."
He then talks about moving down to Scarsdale, which is an affluent community in Westchester Country, NY.
He gets annoyed when his "Sweet thing from Boston" is so young she doesn't even know who Aretha Franklin is and he discovers they have little in common to talk about. But he acknowledges that he's just being old and cranky. A little Jose Cuervo, some fine Columbian, and all is right with the world once again.
So I have no idea where you get high-school dropout skank from all that! Too funny.