Here are Sweep's brl stamps, which I was anxious to see. Cockerill Sambre was the major Belgian steel maker, equivalent to Krupp or Vickers, but I'll need to research their mark.
http://www.hfinster.de/StahlArt2/archive-CockerillLiege-en.html"Seraing is in Liège province, Wallonia region, eastern Belgium. It lies along the Meuse River, 6 miles (10 km) upstream from Liège. Seraing is a historic hub of Belgium's iron, steel, and machine-building industries. In 1817 the English industrialist John Cockerill founded in Seraing what was to become one of the largest ironmaking and machinery complexes in Europe, Cockerill-Sambre, and was the first to use the Bessemer process in steel production (1863)."
Some Browning patent Fabrique-Nationale-Herstal very early versions of the A5 shipped to the U.S. between 1903 and 1909 are marked Cockerill Steel.
That looks as much like a twisted snake as a 'S'??
