I hate to mention this but the rear sight is also on backward. This is really not good because it isn't supposed to even fit that way and has been forced into position. My thought would be to drop this one like a hot potato and try again later. If there is this much poor work/underhanded stuff, what else isn't right? I hate to also mention that if there were no part swapping going on, this probably would never have happened.
I would look for an NRA sold carbine. There are quite a few out and about, some were sold just as they went from factory to storage to NRA most being late Winchester and Inland guns. The average NRA gun has been rebuilt with upgrades and usually have the bayonet lug which is an asset for shooting. You will most likely receive a carbine in great shape with all the latest/best parts which has a lot going for it. I can't see sticking with this carbine you got here, you are looking at what? Done by whom? Costing what to make right?