An original poster for Tarzan the Ape Man (1932) is valued at $40,000-80,000.
It will be sold at Heritage Auctions' movie posters sale in Dallas on November 21-22.
The film was the first in the popular Tarzan series, starring Johnny Weissmuller and Maureen O'Sullivan in their iconic roles as Tarzan and Jane.
Heritage explains this is "the first time we have ever seen the other style one sheet for the first Johnny Weissmuller Tarzan film.
"Never seen for decades, this original 1932 poster (unlike the other style one sheet) actually portrays Weissmuller and co-star Maureen O'Sullivan as they appear in the film.
"The discovery of the only known copy of this one sheet is incredible!"
The lot has benefitted from subtle restoration, with the pinholes in the corners and damage to the lettering repaired.
A window card for Frankenstein (1932) carries an estimate of $30,000-60,000.
The auction house comments: "Posters for this film have always been infamously difficult to find.
"Only a small handful of one sheets including one teaser, one six sheet, one three sheet, one insert, and a restored half sheet are all that have appeared of the posters, not including lobby cards."
The present lot is one of only a handful of window cards, making it a solid proposition for the serious collector.
A rare Frankenstein insert poster sold for $263,000 at Heritage Auctions in 2013.
Please sign up to our free newsletter to receive exciting news about movie memorabilia auctions.