On a slow afternoon at the Musée Mécanique in Fisherman’s Wharf, proprietor Dan Zelinsky roller skates past dozens of arcade machines that date to the late 1800s, then skids to a stop at a majestic Wurlitzer organ. He slides in a quarter, and 130 pipes ring out a carnival version of the Beach Boys’ “Surfer Girl.”

If there were a soundtrack to one’s childhood, it would be reminiscent of this. The impossibly beautiful tones ring out with an almost unreal clarity.

“That was first installed in a merry-go-round in 1917 in Tennessee,” said Zelinsky, as his 67-year-old eyes tear up with nostalgia. “I don’t know how many owners it’s had since then, but it’s mine now. And we’re going to keep it performing as long as possible. Matter of fact, I’m going to oil a little bit of it, because I know it needs it.”

Musée Mécanique’s collection of antique games have been a tourist curiosity on the Wharf since around 2001 (make sure to check out the slideshow above, especially if you've never been). Before then the arcade lived on the lower terrace of the Cliff House, before that in Tiburon under The Dock restaurant, and before that the machines filled Zelinsky’s parents’ basement in a house near the Presidio. His father began the collection at age 11 and passed the obsession onto his son, who said he sees it as his duty to preserve these relics of old-timey amusement.

Zelinsky recently added Tetris and Donkey Kong, but the real draw are the pre-World War II antique machines that can sell at auction for up to six figures. With a handful of quarters, you can see 3D slide photos of the 1906 fires, send a precarious Ferris Wheel made of toothpicks spinning, or test your arm-wrestling strength in a game that apparently infuriated Julie Andrews during the filming of “Princess Diaries,” according to Zelinsky.

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Not surprisingly, arcade games literally made of toothpicks often break. It might seem like a kid’s dream to repair arcade games, but Zelinsky initially only became interested in their mechanics out of necessity once he was operating Musée himself.

“Growing up with them it was second nature. It was my Dad’s hobby, I never paid any attention to it,” said Zelinsky. “When the guys that used to do the repairs would pass away, all of a sudden I had an arcade of broken stuff. That’s when you change your focus. Every time I hired someone to do something, I just paid as much attention as possible.”

Over time Zelinsky has become a walking cartoon toolbox. His belt looks out of a ‘60s Batman episode — the buckle unfolds into a multi-tool and a steel box holsters his cell phone. Screwdrivers hang from a metal pocket protector. A name-tag simply says “I work here.” And a yellow bungee-cord suspender wraps over his blue workshirt, with a tiny rubber ducky stuck to his shoulder.

“That’s my wingman,” jokes Zelinsky.

In addition to that duck, four other employees help keep the games functioning. Hit a red buzzer on the wall of the back of the arcade and someone will open the door to their workshop. It’s a tinkerer’s palace, complete with drawers full of pinball parts, a vintage vertical milling machine (“the 3D printer of mechanics”), a belt sander, a horizontal saw, and a metal lathe, which Zelinsky uses to build out-of-print parts.

“A metal lathe is a way to make any damn thing you want. I used to make new wheels for my kids’ slot cars. There’s so much that it can do,” said Zelinsky.

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Also not surprising, some of the themes in the games have not aged well. A quarter can make an executioner’s noose drop, show a pin-up model photo with a risqué amount of cleavage (for the ‘30s) and stir to life a dragon hiding in the closet of an opium den.

There’s nothing overtly derogatory, but the stereotypes do make people uncomfortable. When asked about the more controversial games, Zelinsky posits that the themes are in the eyes of the beholder. “Everyone has their own interpretation,” he said, and notes that most antique games like this reside in museums. “If you change it, you’re changing the art form. You’re changing history.”

Although an obsessive collector who has spent decades hunting down specific machines, Zelinsky doesn’t keep any games at home. Every machine sits out on the floor ready to be played, even ones that look expensive enough to warrant a do-not-touch sign. He’s never designed a game himself but has spent so much time tinkering with them that he feels a sense of ownership and pride. His favorite thing about repairing machines is simply seeing people enjoy them again.

“It’s like if you’re a singer, and your album is in a jukebox in a restaurant and somebody picks your song, that’s pretty cool. That’s like what they do here, they find one of your songs and they decide to play it.”

Dan Gentile is a digital editor at SFGATE. Email: [email protected] | Twitter: @Dannosphere