“89” or “Eighty-nine” (a movie star is in the store)

 
Newspapers.com
10 June 1929, Pittsburgh (PA) Post-Gazette, “Pittsburghesque” by Charles F. Danver, pg. 8, col. 6:
The Soda Jerkers’ Code.
The young bartenders in one of those big soda emporiums downtown have a secret code. They use it in relaying orders behind the bar.
(...)
“Eighty-nine!” (Look at the legs under the table.)
 
Newspapers.com
23 May 1933, Courier-Post (Camden, NJ), “On Broadway” by Walter Winchell, pg. 10, col. 4:
Code.
A Hollywood soda-jerker forwards this glossary of soda-fountain lingo out there…“Shoot one” and “Draw one” is one coke and one coffee…“Shoot one in the red!” means a cherry coke…An “echo” is a repeat order…“Eighty-six” means all out of it…“Eighty-one” is a glass of water…“Thirteen” means one of the big bosses is drifting around…A “red ball” is an orangeade…“Squeeze one” is a limeade…“Eighty-nine” means that a movie player of importance is in the store, and “Twisted, choke and make it cackle!” means a chocolate malted milk - with an egg in it.
 
10 July 1938, Galveston (TX) Daily News, pg. 4, col. 7:
Car-Hop Jargon Complicated, but
If Mastered Is Never Forgotten
And Makes Taking Orders Simple
(...)
“Eighty”—a glass of water. Add one for each additional glass. However, “eighty-six” shouted by the man or girl behind the fountain (Col. 8—ed.) usually means, “We’re out of that. Try something else.” In some places, “eighty-nine” means that an attractive girl has entered the place, and all accordingly turn to look at her.
 
 
16 April 1940, Paris (TX) News, “Drug Store Slang Makes Etymologists Blush,” pg. 8, cols. 2-3:
If you just want a glass of water, “80” is what the soda jerker will call out. The number of glasses of water ordered is signified by the number added to 80—in other words, 82 means two glasses of water, 83 means three glasses of water, and so on. The number 86, however, means “we don’t have any,” and 89 means an attractive girl is coming in.