Ford Model B Cabriolet
The Model B produced between 1931 and 1934. It was a updated version of the Model A and was replaced by the 1935 Ford Model 48. Strictly speaking, the Model B was a four-cylinder car with an improved version of the engine used in the Model A.
Up to this time, Ford had produced only one "model" at each time with range of body options and retained the idea of a single basic platform, despite the engine choice and two associated model designations.
Source: Wikipedia, 2011