I do not have the tool to remove the eyepiece assembly to see what is in that end of the scope. The M2 Scope which came out before the M3 scope is much rarer. It fits on the M3 mounting bar and lines up with windage adjustment nuts at rear of mounting bar (See Photos). I have no idea if it works. The carbine and mounting bar assembly were just used to show how the scope mounts to a carbine.The item "M1 M2 M3 Carbine M2 Infrared Sniper Scope Korean War Night Vision" is in sale since Tuesday, September 06, 2016. This item is in the category "Collectibles\Militaria\Korea (1950-53)\Original Period Items". The seller is "northstar1gazer" and is located in Otis, Massachusetts. This item can be shipped to United States.