I see what you are talking about. It is called a rear baffle and sets just ahead of the bolt. If for some reason, the time gets close and you still do not have it, I have a spare that I could send you. When you get yours, then you could send it to me to replace or send me back the old one. It is a bolt that came out of a Stevens 200, but I think it will fit your rifle.
Good Luck and Good Shooting