Odd Attachment Device on WW1 Collar Disk

[atb]

Picked this up today at the Gettysburg Antique Militaria show. It's a Coast Artillery Corps disk with what seems to be a smaller than usual shell within an oval. On the reverse are the remains of two pins. At first I thought there had been a pinback device, but the pins look like they were straight. I don't believe the disk is a reproduction. I'm still working on label removal.

 

[atb]

Maybe fold/bend over pins broken from use?

[268th C.A.]

Agree with atb

[KurtA]

Probably was a pinback.  Has remnants of wire catch and base for pin hinge. Looks totally original to me.

[atb]

22 minutes ago, KurtA said:

Probably was a pinback.  Has remnants of wire catch and base for pin hinge. Looks totally original to me.

Either way, pinback or bent pins, I am happy to have gotten it for $5.00.

[JohnK83882]

Could be theater made, French or German. Here's the back of a US collar disk made in France. Yours might have been made to attach to some hardware. I've seen collar disks attached to stuff.

 

[JohnK83882]

I have two of the french disks. Here's a pic of them from the side. 

[atb]

28 minutes ago, JohnK83882 said:

I have two of the french disks. Here's a pic of them from the side. 

I've always considered the pinbacks like on the left as US-made. I think some of the published references say this, too.

[JohnK83882]

9 minutes ago, atb said:

I've always considered the pinbacks like on the left as US-made. I think some of the published references say this, too.

Entirely possible. 

[Remark]

The shell size is just a variation.  I have coastal artillery discs with several different sized shells.   I attached pictures of 2 below.

 

As to the backing, I suspect the pins you see may have been added later.  I don't recall having seen y mounting devices that close to the edge of any other disc.   When you remove the sticker you will likely see the remains of a previous screw post attachment or some other evidence of a post being previously mounted.

[atb]

4 hours ago, Remark said:

The shell size is just a variation.  I have coastal artillery discs with several different sized shells.   I attached pictures of 2 below.

 

As to the backing, I suspect the pins you see may have been added later.  I don't recall having seen y mounting devices that close to the edge of any other disc.   When you remove the sticker you will likely see the remains of a previous screw post attachment or some other evidence of a post being previously mounted.

Ver nice examples. I did get the sticker off. The reverse is smooth with no evidence of anything having been removed. Based on the placement and configuration of the pin stubs, to me the logical explanations are prongs that were meant to be bent over, or a reproduction with pins for clutch-type fasteners, or pins for mounting to a maker's or salesman's sample board.

[atb]

And, the sticker may have been a maker's for inventory tag.