“You give us thirty-two minutes—you don’t get it back.”
WINS is a NYC news station with the slogan " You give us 22 minutes, we give you the world."
Lester Traipse across the street...in the company of a blond bombshell
I would never argue that Pynchon explicitly had the "Master of Suspense" in mind when he wrote this paragraph, but it certainly does have a Hitchcockian vibe. "Vertigo," anyone?
Daphne and Wilma's
Could this be an allusion to Daphne and Velma, two female detectives (like our Maxine) from the cartoon Scooby Doo? ... with a dash of the Flintstones.
The Officina in Santa Maria Novella
Actually "Officina di Santa Maria Novella", one of the oldest pharmacies of the world, now a producer of perfumes and cosmetics; there is also a museum. Source
Possibly a reference to Stanley M. Moskowitz (c. 1937 - June 29, 2006) who was a top official of the Central Intelligence Agency. Moskowitz was born in the Bronx and graduated from Alfred University. While attending graduate school at Duke University, he left to join the CIA in 1962, where he worked for over four decades. In the 1980s, he was a national intelligence officer for Russia and Eastern Europe and became congressional liaison, serving under two CIA directors. From 1995-1999, he was the station chief in Israel, where he tried with some success to mediate between the Israelis and Palestinians. His term ended soon after the Benjamin Netanyahu government became dissatisfied with his role and an Israeli paper outed his identity as CIA station chief. From WIKI.
Little Black Dress
"And whoop there it is"
I believe this is referring to Conkling's erection, where he catches Maxine checking it out and there's an awkward moment, to say the least...
And "Whoomp! (There It Is)" was a top-ten hit for the group Tag Team in 1993. If, for some reason, you want to hear it, here you go.
the deluge after them
The deluge here is both real and metaphorical, see Après nous le déluge.
The Post, for whom the Cold War still emits a warm nostalgic glow, loves stores like this, so the screaming began, KGB assassination squads running loose through the city and so forth, and this sort of thing would go on for the better part of a week.
Surely the author is familiar first hand with the Post coverage of the arrest and deportation of Russian spy Anna Chapman in 2010,  WIKI . Also noteworthy is Chapman's characterization of her time in New York City by citing Dickens: "It was the best of times, it was the worst of times." 
Luminol is used by forensic investigators to detect trace amounts of blood left at crime scenes, as it reacts with iron found in hemoglobin. From WIKI.
before the gunsmoke
This phrase is missing in the 2014 Vintage paperback edition, probably after someone realized that the blade was "spring-propelled".
just set it on stun
an old Star Trek cliche
9:30 . . .
A hardcore punk club in DC Wiki.
As Scarlett O'Hara observes . . .
The last line of Gone with the Wind: "After all, tomorrow is another day."
Perhaps worth quoting a few more lines from the ending.
"With the spirit of her people who would not know defeat, even when it stared them in the face, she raised her chin. She could get Rhett back. She knew she could. There had never been a man she couldn't get, once she set her mind upon him.
"I'll think of it all tomorrow, at Tara. I can stand it then. Tomorrow, I'll think of some way to get him back. After all, tomorrow is another day."
Complete text of Gone with the Wind.