The vast majority of Huttl saxophones are Hammerschmidt stencils, like the example below. So, check out the Hammerschmidt page!
Quoting from Horn-U-Copia:
Anton Konrad Huttl started his company in 1877. Huttl Logo Early in the 20th century, they produced brass telescopic instruments, in which the conical tubing was replaced with a series of cylindrical sections gradually increasing the diameter. The company received awards. (1878 Paris, 1880 Melbourne, 1901 Copenhagen-Stockholm, 1902 Decín, 1903 Ústí nad Labem, 1903 Osaka, 1910 Buenos Aires). The company advertised in 1913 that they had the largest most modern factory in Austria-Hungary and Germany.
In 1945, the company was Nationalized, and they relocated to South Wales. In 1954 the company moved to Baiersdorf.
Huttl also had a factory in Canada that closed down around 1975-6. It primarily assembled, buffed and lacquered horns made from parts sent from Germany. Those horns were marked, Western Germany, presumably for Baiersdorf, Germany.
The assets were then purchased by the Chris Kratt Instrument Company which was an import business marketing Huttl instruments. They supposedly continued to make instruments as before but without the Huttl label. In 1979, The factory ceased to exist.