Looking for a low-voltage motor? A bin of surgical scissors? Inflatable busts of Nobel-winning geneticist Barbara McClintock? Photo slides from a stranger's 1970s vacation?

You can find all of the above on the shelves of St. Paul's Ax-Man Surplus, which for more than 50 years has sold a delightfully improbable collection of goods that are valued not for what they are, but for what they might become — inventions, sculptures, science experiments or seriously creepy Halloween displays.

There are rows of mannequin heads, glassware decorated for occasions past ("Prom 2017") and a giant iron lung in the middle of the "material, crafts, kitchen" aisle. Stage lights fill one display.

There's a giant bin of metal hamster wheels and a trove of pingpong balls decorated to look like eyeballs. Down another aisle sits a collection of oddly shaped bags with a sign reading "Shrunken head briefcase! Keeping those little guys safe since 1974! $3.95," which seems designed to ­entertain as much as entice.

Now on its third owner, Ax-Man was created by a unique alchemy of sorts — a summer hire ended up changing a standard discount store into a repository where castoff materials find new lives. The store has managed to survive, sensibility intact, even as retail, manufacturing and the types of overstock goods have changed.

It has remained at Fry Street and University Avenue since 1966, despite significant changes in the Midway neighborhood that surrounds it. Once home to an "auto row" of car dealerships, the area now boasts a light rail corridor. Allianz Field rises nearby.

Started by a clothing liquidator named Jess Liberman, the store was called the Man With the Ax (to give people the idea that the prices were seriously chopped) and sold more normal discount goods, such as luggage and suits.

When University of Minnesota art student David Gray got a summer job at the store in 1969, he started seeking out industrial and mechanical surplus, the kinds of scrap-yard materials he used in his sculptures.

"I realized there were lots of companies out there that didn't know what to do with their leftover parts," Gray said. "And so we decided to start buying that stuff. And I said we should just put it out because, you know, the starving art students, and theater people, and tinkerers, and inventors, the scientists and so forth, would find a use for it."

He also convinced Liberman to be more playful with the store signage, with messages that helped customers see the possibility in spare parts and castoff electronics.

"I realized pretty early on that if I watched people, you could see what I call the twinkle in their eyes," Gray said. "And their brains might connect just by looking at some oddity. Everybody saw different things in the very same item."

Gray became a partner in the business, eventually acquiring it. In 2001, he sold it to Jim Segal.

Segal was trying to kill time before a lunch at the Embers that was once nearby when he first wandered into the store. He was blown away.

"There's nothing really like the Ax-Man. Not in Minnesota, not in the nation," he said.

Since buying the business, which includes locations in Fridley and St. Louis Park, he's worked to keep the curiosity-shop vibe, especially in the St. Paul store.

It helps that some of the staffers have been there for decades.

Janette Larson, the store's longtime office manager, still remembers the day she started work in September 1988. Someone came in and bought a life-size fire truck replica and she had to help figure out how to get it outside.

Larson said the store is largely the same as it always was. "Mostly, the inside is the same. We still have the iron lung," she said with a chuckle. "I don't like change. That's probably why I've stayed here for so long."

During Segal's years running Ax-Man, his favorite surplus buy has been an entire 1960s-era military field hospital that had been in storage for decades. It took a while, but it has been sold, piece by piece.

After all, parts and pieces are what the store's all about.

"We buy all sorts of fun stuff. We bought a truckload of doll parts. With our customers, you know, someone could offer me the whole doll, and we wouldn't have that much interest," he said.

But put the parts in separate bins — heads, arms, legs — and shoppers are intrigued.

"Luckily, people don't take us too seriously," Segal said. "We don't take ourselves too seriously. We're trying to have fun."