found this.

[dr1ftd1gger]

What do you folks think? I got a few ideas. But I think my imagination is humoring me.

 

[ARC]

What size...? Can you put a quarter beside it?

Looks like a very worn old "zinc" for boat.

 

[dr1ftd1gger]

 

[ARC]

Looks like a well worn "anode" from a boat...
This piece of metal is called a sacrificial anode, and most often it is zinc. In fact, most boaters refer to sacrificial anodes simply as zincs.
Here is what it may have looked like new...

 

[ivan salis]

some tokens were made of zinc -- look at dinsmore dairy tokens *

 

[lost items recovery]

....

 

[Doc Arey]

Sinker?

 

[Brother Al]

Without a doubt its a sort of square thing with sort of rounded corners and a hole in the center. Thats not imagination. :-D

 

[dr1ftd1gger]

Well I thought it looked a little cross-esque

 

[SonnyFl]

Looks like one of those Lead thingamagigs?

 

[gamiller]

Without a doubt its a sort of square thing with sort of rounded corners and a hole in the center. Thats not imagination. :-D

Brother Al nailed it.

 

[mnruxpin]

pirate ninja throwing star

 

[Digging Deeper]

Valve handle or knob.