A company I worked for had a mechanical tool from the 19th century, with ornate cast scrolled legs. They couldn't find 60 cycle C frame motors that would fit the mount, and found that 50 cycle motors imported from England, and run at 60 cycles until they burned out were actually cheaper, on a per unit basis.
Years ago I was doing electrical work in SO Cal and kept running into failed 50Hz motors. Turned out large parts of the area was 50hz when service started.