23rd Corps, 75th Regiment?

[Chris]

I just bought this in a lot and don't even have it in hand yet. It is probably a half- dollar size insignia. To me, it looks like a kepi patch. The shield is consistent with the 23rd Corps badge. On the reverse is the remnants of red wool. I am guessing the front was probably red wool and the red is gone, perhaps mothed away? But red would be consistent with the 1st Division, 23rd Corps. And the "75" is a regimental number? In any case, I wanted to get some expert input on my theoretical ID. Thanks for any feedback.