Listen to Woodsy Alex, he has it exactly right. If you see a receiver with a number of stake marks on it you know it is not the original sight!. However, you have to take into account that correct field mods were made when they upgraded the sights. So really, after considering that subject, you have to consider the condition of the Carbine overall, to be able to judge it's "originality". There's a big thing going on about "shooter Carbines" and "collectable Carbines", people want them for different purposes, as long as they are all preserved, OK by me. Mike.