“Rather than being more than a century old, the clocks were approximately five years old, and they were manufactured in Beijing by a company that sells virtually identical clocks as modern reproductions for about $20,000 a piece,” the buyer’s lawyer, Ted Poretz, wrote in the lawsuit filed in federal court.

The complicated case highlights the difficulty of adjudicating what is real and what is fake in this market for such elaborate — and ostensibly centuries-old — timepieces.

In the court papers and an interview, Mr. Poretz said he had been able to identify the maker of the clocks as Li Qiusheng, the owner of the Tianjin Edwin Clock Company in Tianjin, a port city southeast of Beijing. He said the clocks appear to have been brought to market in the United States by Mr. Li’s son, Edwin, a California dealer who sells clocks under the name EM Time Company.

Li Qiusheng, reached by telephone, disputed the suggestion that he produced fakes. He said the clocks were genuine, dating to the 1920s, though he acknowledged that old clocks often need repairs that require using modern parts.

“When the clock doesn’t work, you need to replace the components,” he said. “If a wheel gear is broken, for example, you need to replace it with a new one.”

A lawyer for his son, Edwin, Steve Sherman, noted that neither Li had been named by the buyer as a defendant in the suit. He said the son had no financial interest in the clocks and had only acted as an intermediary for his father. He “was basically acting as an interpreter,” Mr. Sherman said.