Unknown Confederate Musket Buttplate CSA (Mississippi Type Rifle)

Description

This is an original Civil War musket or rifle buttplate. It’s marked CSA but I don’t know if that is a period stamp or later. I originally thought it was for a Mississippi rifle but the dimensions are not correct. It does not have a cutout for the patch box. Some educated people suggested it could be from a Confederate copy of a Mississippi rifle but I was unable to find buttplate pictures to confirm or not. Notice how long the tang is after the top screw. I figure someone out there can identify this. Feel free to ask questions.