Army U.S. Collar Insignia Device (Dating)

[Chief D]

I am looking to date this screw back device. I have not seen one "rolled" or "curved". Also it is connected in the middle. Any help would be appreciated. Additionally if any information can be read on dating these devices.

[patches]

That is the U.S. Device from an Enlisted Man's U.S. Collar Disc, probably a Domed or Semi Domed type of the late 40s into the 50s.

[Chief D]

Thank you so much! That makes a lot of scene. I appreciate the guidance.

 

[patches]

Here's shot of the back of one showing how the device is attached, a counter sunk circular clutch plate.