Cuff CORPS button and ?

[Smilodon]

First CORPS button I have found in this size, very small, I guess cuff button. This one is also different than what I could find online. Don't know if there is any backmark on this one as it is still covered. Along with some usual musket balls, found a few more plain buttons and the small rectangle brass thing with cut corners and the majority of the attachment prongs on the back. I would say about 1" X 1/2" Not sure what it is or if it has anything under the heavy patina. Any ideas?

 

[TNGUNS]

Wow, great button and anxious to see if anyone knows what the small plate is. Congrats

 

[jewelerguy]

sweet artillery button!

 

[ekeisler]

War of 1812 artillery corps button. Great finds!
Here's one I found online.

 

[dig kzoo]

Killer finds! Congrats!!!

 

[dirtlooter]

very awesome button