(CNN) The homeless man found a ratty picture of Bambi, the Disney character, in a trash bin and brought it to antique dealer Alexander Archbold to get a few bucks.

The men had made similar transactions before, and Archbold -- who owns the Curiosity Inc. store in Edmonton, Canada -- is generally quick with his appraisals. But this one was different.

At first Archbold thought he had bought a replica of an animation cel from the 1980s or 1990s. He thought if he removed the broken frame and cleaned it up, the picture might fetch $80 to $100.

He paid the homeless man, Adam Gillian, $20 for it.

But when he it took it out of the frame and flipped it over, Archbold discovered an old certificate of authenticity. Even more surprising: It had a copyright date of 1937. "Bambi" hit theaters in 1942.

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