Fernando, I presented the sword in a separate thread previously. See:
http://www.vikingsword.com/vb/showthread.php?t=23528
I thought I would follow up on the four dots mark in this thread dealing specifically with marks, and see if someone recognized them. Are your [small] cannons from a particular geographic location? Could they be the mark of a foundry producing iron? Perhaps the cannons were cast at this foundry and then marked accordingly?