Josef Falk began as an employee (salesman) of Georges Carette, but in 1895 he founded his own company. J. Falk produced many model steam engines, including some rather large overtypes. In 1912 Falk bought out Schoenner steam engines line for which he already produced engines since 1907.
After the First World War, Falk worked together with Bing, producing a some engines with the combined JF/BW label.
In 1934 the Schaller Bros. bought out Falk and the manufacturing of model steam engines ceased.
What's it worth? Take a look at this Falk price guide: sold listings for a value indication.