I am aware of THE gray blanket too. Mine doesn't have the power. I could have used my O.D. Green one in the wife's car, but I thought the gray would be appropriate for the South.

I don't know if you can see them in my picture but this gun does have old cartouches on the left side. That would have probably been from the North. At some point it ended up with the CSA.
The "JR" on the left has the most wear over it, so one could figure he was the first to acquire it. Then the "PL" on the right side is newer and maybe the second owner?
The MJ seems to go with the NC Inf CSA, so it may be the "nick name" of the Company, Regiment or Battalion, an example would be the 16th Regiment North Carolina Infantry was known as "Burke Tigers". Other units also had nick names.
Just thinking out loud here.