Help Identify Coin

To me it looks like it was an old Tab of some sort, also looks like maybe the pull part was on the left bent edge of the piece. Not a coin. If it was a coin, there is really no telling what it was, no details remaining.

2nd on the grease tube type cap, I have some in the sop they fit a gun that is about a quarter in dia. Also too thin to be of any usefulness as token ,coin or bangle.

Bridle chonchos generally have some means of either sliding the strap through two rectangle slots. Or some from of loop on one side to fasten it to the straps. Most aren't plain as the have flower or some other motifs on the faces.

Sad as it is it looks to be covered in rust which would mean it is ferrous material. And some times metal detector finds are just junk. Not trying to be nasty, but don't know what you mean by coin groves around the edge. All that is visible in the one ring, If you mean the vertical lines on the edge that doesn't mean it is a coin.