Now that Midtown Manhattan has become a playground for the superrich, could it be time to bring back the oak-paneled mansions of the robber-baron era? On West 54th Street, two limestone-and-brick homes built by the architecture firm McKim, Mead & White for James J. Goodwin, a cousin and business partner of financier J. Pierpont Morgan, are about to go on the market as a single $65 million listing. Brokers are positioning the property, known as the James J. Goodwin residence, as a low-rise, more human-scale alternative to the high-price megatowers under development in the area. Its 50-foot-wide property at 9-11 W. 54th St., across from the Museum of Modern Art, could be transformed back into a 22,500-square-foot single-family home and one of the largest mansions in Manhattan. Only a handful of mansions in the borough are wider, city tax records show. It is a landmark building, and many of its interior rooms, as well as the entry and staircase, with richly carved details, have been restored to their original grandeur after a period of disrepair when it served as a prep school. Midtown, once a residential backwater, is now home to the most expensive home ever sold in New York, a $100.5 million penthouse at One57 on West 57th Street. Eight more towers are on the way in a part of town that real-estate agents now call “Billionaire’s Row.” “In the last 10 years, the Midtown area has evolved to be extremely residential and a real luxury market,” said Cathy Franklin, a broker with the Corcoran Group who has the One57 listing. The houses, now combined, also come with an amenity that might enhance its appeal for a financial mogul: safes. One, a walk-in safe for the family silver, is located in an octagonal dining room, with the steel entry built into a wood-paneled closet door. The other is a 17-foot-deep bank vault behind a guard station with bulletproof windows. James Goodwin, who was a director of the Erie Railroad and two insurance companies, had the double house built in 1898 by McKim, Mead & White, an influential firm whose classically inspired designs include the former Pennsylvania Station, the Brooklyn Museum and the main campus of Columbia University, as well as the University Club, a few doors down on West 54th Street and Fifth Avenue. He lived in 11 W. 54th St., the wider of the two houses, and family members or renters lived in the other, according to the city’s Landmarks Preservation Commission. He died in 1915, and his wife Josephine lived there for many years. In the 1940s, the house was sold, and for more than three decades it was the Rhodes Preparatory School. In 1979, the United States Trust Company of New York bought the property and turned it into an office for its wealthy clients, restoring paneling and carved details that had been destroyed during its years as a school. David G. De Long, an architecture professor emeritus at the University of Pennsylvania who was a consultant for the bank, said original drawings were used to recreate long-lost interior spaces. Fluted wood columns were carved from solid German oak, because American oak at the time didn’t match the original. Scrapes of old wallpaper were found and used to recreate original flocked wall coverings, he said. There are carved acorns on the stairs, intricate plaster designs on the ceilings and pillars at the entry and stair landings. At the rear of the building, the bank built a modern space for its tellers, complete with a row of video cameras pointing at the cash drawers. Unites States Trust was sold to Charles Schwab in 2000 and later to Bank of America. In 2009, Bank of America sold the 54th Street property for $29 million to two real-estate groups, DLJ Real EstateCapital Partners LLC and J.D. Carlisle. The two groups were looking for “irreplaceable assets in unmatched locations,” a DLJ spokesman said. They thought the site could also be part of a real estate assemblage. After leaving it vacant for more than five years, they decided to put it on the market this year. While condominiums on West 57th Street are now selling for more than $9,000 a square foot, the Goodwin house is listed for less than a third of that, at just under $2,900 a square foot, a relative bargain. But brokers not involved in the sale noted that townhouses, by their nature, lack the king-of-the-world views of high-rises overlooking the New York skyline and Central Park. The house could also have considerable value as high-end office space, consulate or private club, Corcoran’s Ms. Franklin said. When a smaller, 25-foot wide Beaux-Arts mansion next door went on the market in 2012 it was marketed as a “trophy office space” also asking $65 million. It eventually sold for $40 million, and is now the New York office of IMG Artists, a music booking agency.