CC, I don't mean to brush you off but you should post this question at
www.jouster.com. It's more a M-1 Garand site but there are a lot of carbine owners that might be able to point you in the right direction. If you had brought the rifle to me, we'd be doing the same thing you are right now. Another source for at least information might be the tech support staff at Brownells.
www.brownells.com. George