The Mysterious Zack Hamilton

In the final fifteen minutes of The Mysterious Monsters, during the segment that opens with Peter Graves announcing, "Exhibit H: The Still Photographs", the viewer is shown a very early and very famous photo of an alleged Bigfoot, a photo that is still being circulated and debated today. It's a murky, poor-quality black and white image of a large humanoid figure in the distance, apparently retreating from the photographer. Visible in the foreground are some low-hanging pine branches. Before moving on to the next photo, Graves says only that the snapshot was "taken in 1965 in Oregon by an experienced woodsman, Zack Hamilton."
A book entitled Bigfoot: The Mysterious Monster was written by Robert and Frances Guenette to accompany the release of the film, and the authors filled in a few more of the details. As it turns out, the photo wasn't taken in 1965--it was published on December 14 of that year in the San Francisco Chronicle (beneath the headline "Is This the Dread Man-Animal?"). It had been taken five years earlier and developed at a San Francisco camera shop. The negative had been dropped off by someone identifying himself as Zack Hamilton, but Mr. Hamilton never returned to pick up his photographs. On whose authority do we have it that Hamilton was a "woodsman"? The assistant manager of the camera shop, who--according to the Guenettes--told the Chronicle, "I don't think an old woodsman could fake a thing like that." Whether Hamilton entered the shop in hiking boots with a bundle of cordwood strapped to his back or simply told the assistant manager that he was an outdoorsman is unclear. (It would help to have the original newspaper article but, despite my best efforts, I've been unable to find it online.) Also open to question is how the location of the photo--Three Sisters Wilderness in Oregon--is known. At any rate, Hamilton's pictures remained unclaimed at the camera shop for five years, and the assistant manager finally took the Bigfoot photo to the Chronicle.
The photograph itself is unimpressive, and likely a fake. But who was Zack Hamilton? If he had perpetrated a hoax in the expectation of profiting from it, why didn't he ever come back to get his pictures? "Zack Hamilton could be dead," the Guenettes speculated. "That would explain some of the mystery." And it does, sort of. I consulted the Social Security Death Index and found a Zack Hamilton who died in California in November 1962, at the age of 69. But if he's the right man, and if the camera shop manager had been hanging onto the picture for five years, that means that Hamilton dropped off his negative in late 1960 or early 1961...which gave him more than enough time to claim his photos before he died. Why didn't he? Did someone hoax Hamilton? If so, why hasn't this person come forward in the nearly fifty years since the photograph was published?
I can't answer these questions. It's unlikely, but perhaps Hamilton still has living relatives who could clear up the mystery? After five decades as a disreputable phantom presence in the annals of cryptozoology, Zack Hamilton--whoever he was and whatever his motives--might possibly be restored to full humanity. But time's a-wastin'.