Henry Werro (1896-1971) became a violin maker like his father Jean. He was internationally recognized as a restorer and instrument maker. He received numerous awards and was president of the Swiss Violinmakers' Association. His specialist knowledge of old instruments made him a sought-after expert and renowned dealer. Time and again, he had exclusive violins such as Antonio Stradivari's "Lady Blunt" in his care.

In the 1950s, Werro became involved in the so-called Swiss Violin War, in which the business practices of some violin makers were investigated. It concerned the trade in falsely attributed instruments. The trial attracted a great deal of media interest, as international experts were also invited as witnesses. in 1958, Werro was convicted of fraud, forgery and coercion.