An Auburn bookstore manager believes he may have a working copy of a Stephen King manuscript that eventually became “Under the Dome,” a novel that was turned into a TV series.

Walter Lantz, who manages Artios Books, said the text, which is a copy of an original typed manuscript, appears to be pages from a never-published King book called “The Cannibals.” It includes hand-penned editorial changes that Lantz said could have been made by the famous Bangor horror writer himself.

The text surfaced last month in a collection of Stephen King books sold to the store by an Auburn woman who was raising money to pay for a relative’s funeral. Lantz said the collection included a number of lesser-known King titles, such as “The Colorado Kid,” in their original shrink-wrap. Lantz said the woman didn’t know how the text came to be in her collection.

Lantz said the manuscript numbers 122 pages. Lantz said if it turns out to be what he thinks it is, he will probably sell it and give the collector a commission, up to 20 percent depending on how much it is worth. But first he wants to talk to King.

“I need to talk to him to know what I have,” said Lantz.

Lantz said Marsha DeFilippo, King’s assistant, visited the store Friday and took about 20 photographs of the work.

“She was very excited,” said Lantz.

He has not heard back from DeFilippo. She could not be reached for comment Saturday.

King wrote about the metamorphosis of “The Cannibals” into “Under the Dome” on his website. He said he started the project in 1978 but lost that 70-page manuscript. Several years later he took another stab at it, this time under the working title “The Cannibals.” He got about 500 pages into it before hitting a wall. “Under the Dome” was a partial rewrite of “The Cannibals.” King said he thought that “The Cannibals” manuscript had been lost as well until it resurfaced in 2009, battered and missing a few pages.

The first 60 pages are available on the Stephen King website.

Lantz said he hopes he can get to the bottom of the mystery soon.

“Either Stephen King did this or someone took a copy of it to proofread it for him,” said Lantz.