A number of products I'd call Masterpieces were introduced in the 1930s in Germany, and some models were manufactured for decades. Hard to believe in this age of electronics that seem dated in a year.
In 1933 Leica introduced their model III. Then 35mm still photography was called "Leica Photography" because they introduced the first high-quality, successful 24x36mm format still camera in the mid 1920s. Zeiss waited almost 10 years to respond with their Contax, and in spite of their excellent optics, engineering, and quality, the Contax I was not a great tool to use. So in 1936 they introduced the Contax II as a direct and worthy competitor to the Leica III (by then the IIIa was out with a 1/1000 shutter speed). By 1938 the VW Beetle was developed, although few were made in that decade, in favor or military vehicles.
The Leica III and its a, b, c, d, and f improvements was made until the mid 1950s. Even after the Leica M3 was launched in 1954, a new III version (the g) was marketed in 1957 into the 1960s - about 30 years for the basic design.
The Zeiss Contax II was sold to the end of WWII in 1945, but the factory was captured by the Russians and moved to Kiev, where they made the same model into the 1960s.
Of course the VW Beetle lasted in continuous production (somewhere in the world) until 2004 - so it outlived the cameras. (I have a 2001.)