After standing vacant for years, the historic downtown building at 124-126 Castro Street, known by city historians as the "Weilheimer store," is now set for renovation under a new owner.

For the last two years former owner Terry Klein worked slowly to preserve the historic presence of what may be the oldest commercial building in the city. His family owned the building for over 50 years, and once sold clothing and shoes there when it was "the workingman's store." It's even the place where he met his wife.

It wasn't easy to let go, but due to Klein's recent health problems, he has sold it to Los Altos native Don Imwalle of Imwalle Stegner Development, who plans to restore it by year's end.

"There comes a point in your life when you can only do certain things," Klein said. "I gave it as much as I could to rejuvenate that building to what it was originally. I just had to bail out and hope for the best; that's all I could do."

Built in 1874, the building is said to be the oldest commercial structure in the city, surviving the 1906 earthquake. It has been added to and altered substantially over the years, and the wood posts that once held up the awning for the popular Weilheimer general store -- featuring marks from the thousands of horses that have been hitched to them -- were re-used inside, Klein said. Remnants of history, old bottles and signs, are displayed in the window.

Klein had hoped for a business "that would represent the building to the old-timers and Mountain View pioneers who loved coming in there," but disagreements between him and a sibling over the inherited building stalled his dream.

Imwalle, who closed escrow on the building April 29, seems to enjoy the history of it. "We're going to do a historic retrofit of the facade -- a mid-19th century look," he said. "We have a picture of the way it originally looked, which is quite attractive."

"It's great to see Main Street USA make a comeback," Imwalle said about business trends on Castro Street.

Imwalle credited Klein with saving the building's structure from leaky plumbing a few years ago by giving his restaurant tenants the boot and pulling the walls apart to help them "breathe." He has plans for a large restaurant to take up the interior, but says he is also open to a retail tenant. He said the restoration could take as little a three to four months if there are no delays.

The city zoning administrator extended permits for a restaurant and facade improvements on April 23, despite heavy interest from the city for more retail and fewer restaurants on Castro Street.

"I think Castro Street will see more retail but probably not on the 100 block," where restaurants like Xahn, next door, are a huge hit, Imwalle said. "If you tried to put retail in there by itself it would struggle."

City project planner Melinda Dennis said the city was happy to see the project moving forward. The "highly visible" location across the street from the train station is one of the final pieces of the downtown development "puzzle," she said.

Are you receiving Express, our free daily e-mail edition? See a sample and sign-up for Express.