The label of a violin does not always accurately indicate the maker of the instrument. Many hundreds of thousands of factory produced violins made since the late 1800s bear then name of Antonio Stradivari, who lived from 1644 to 1737. The label that Antonio Stradivari used reads "Antonius Stradivarius Cremonensis Faciebat Anno [year]." Factory instruments often have a fascimile label, printed on artificially aged paper. The words "made in Germany" or "made in Czechoslovakia" may also be printed on the label.
Other noted violin makers have had their work copied on a mass scale. These include Amati, Klotz, Guarneri, Maggini, and others.
One way to determine the value of your instrument is to take it to a reputable violin shop for an appraisal. Many violin shops, including Saint Louis Strings, provide this service.