I brought mine to the yacht club this weekend in hopes that I'd have time to polish some of the patina off and detect additional markings, but never got around to it. Weather was too nice, I was on the water most of the weekend. I did talk to the previous owner about it, all he knows is that it's manganese bronze and that he believes it was new in the late 80s or maybe 1990, so you're right, not an original Hmco anchor. He bought it off another sailor who let it go for the ridiculous price of $50. Even though it's not vintage, I almost feel like I shouldn't sell it at this point. Maybe I'll offer it to my club as a decoration or something. Thanks for the input!