Join Date: Dec 2004
Location: NC, U.S.A.
I've seen this exact marking before (a sort of sailboat or scale design), did research and never found out more on it. The item it was on was a mid-19th c. ax, possibly a boarding piece.
There is a WIDC hanger featured in "Naval Swords' by the renowned P.G.W. Annis. That piece features a single edge cutlass with simple brass knuckle bow and ribbed black iron grip. It is marked 'WIDC No.11' and a block letter GR under crown, ca.1805. The India Dock police patrolled and protected the company docks and ships along the river Thames. They were the predecessors to the Thames Division of Metropolitan Police. These type swords are excessively rare and interesting. I'm in agreement to the dates on your sword, ca. 1805-20. I'm glad you didn't part with it!