Just like the swallows in San Juan Capistrano, the models of California’s missions have returned to Knott’s Berry Farm after an 18-year absence.

On Wednesday, 13 of the restored models went on display, with the other 8 planned for placement over the next few months.

The original models first appeared in the park in 1956. They were commissioned by Walter Knott to be placed along a trail next to the Stagecoach line to keep people from wandering in front of the horse-drawn carriages.

Knott had heard about a set of mission models that had been on display at the 1939 Golden Gate International Exposition in San Francisco.

The man who built them was Leon Bayard de Volo, an immigrant from Italy. He worked for Warner Bros. for many years then started building models of things on contract. Knott commissioned de Volo to build a larger set for the farm.

When completed, they were each housed in dioramas along that trail, renamed the El Camino Real, which is where they stayed into the 1990s. But then they were one by one removed and in 1998, the last two mission models were taken away.

The models were placed in storage on the second floors of the shops in Ghost Town and left there. Stories were written about them on Orange County Historian Chris Jepsen’s blog and several theme park fan websites, calling attention to the missing mission models.

With a change in upper management a few years ago at Cedar Fair, the owners of Knott’s since 1998, came a realization that the history of Knott’s was important, and the decision was made to bring the missions back in 2013.

“It’s an encouraging continuation of Knott’s tradition of being far more than just an amusement park,” said Jepsen, president of the Orange County Historical Society.

But bringing the mission models back involved more than getting them out of storage – they needed to be restored to their previous luster, something that took nearly three years to complete.

The job of restoration was handed to Bob Weir, a veteran woodcarver at Knott’s for more than 20 years.

“They were in sad shape,” he said.

Knott’s officials decided to make the restoration project a small attraction at the park. They created a space in Ghost Town near the barn for the project, where visitors could watch while Weir worked on the models and answered questions as he figured out how to make the missions whole again.

But it wasn’t just a simple restoration; in the 1950s, they were only made to look good from one side, the only side visible. The backs were unfinished.

“They wanted me to finish them so they could be viewed from all four sides,” he said.

To help with his restoration efforts, Weir visited the missions, purchasing books and seeking out drawings to help guide him. He also had to figure out what to use to repair the models.

The wood originally used was pine, but for the restoration, Weir used Birch plywood. For the finished look of the adobe walls, he used a stucco mix, then used acrylics to hand paint everything, including the figures of people – each about two inches tall as the scale was about one inch equaling three feet. He also made molds of the original roofs, casting new roofs with Plaster of Paris.

When he would get one done, the staff at Knott’s would take it back to a warehouse for proper storage then bring him another one. Most of the missions sat on tables that were roughly 5 feet by 7 feet. But the model of Mission San Juan Capistrano was much larger.

“I told them I was done, and then they brought out the other half,” Weir said.

That model measures nearly 12 feet by 12 feet.

After he finished restoring 16 of the missions, his next task was to build, from scratch, the remaining five. The original models could not be found and no one knew what happened to them. By mid-2015, Weir’s job was done. It was time to decide where to put them.

Knott’s officials decided to build small huts in which to place each mission model to protect them from the elements. The huts were wired to provide light, and backdrops to represent the sky were placed inside.

The huts with the mission models have been placed in the same area where they once sat, along the Stagecoach trail.

The park plans to incorporate the models into its education programs during the school year, particularly for those in the fourth grade – many of whom are assigned a report and models of one of the missions.

“The California Mission models hold as much educational value as they do sentimental value for many of our guests,” said Jon Storbeck, general manager of the park.

In March, the park will hold an event called “Early California History Day.” On that day, students will have the chance to bring their own mission models for display, and judged, with the winners awarded prizes from the farm.

Contact the writer: meades@scng.com or follow on twitter @markaeades