The pad below the rear sight base has been milled about .075", (hard to notice}to allow a lower front and rear sight setting. This allows for different rear sight bases to be changed quickly, without having to remove any pins. Also this modification allows the rear sight to have complete travel all the way out to the top. This allows it to be elevated for 1000 yards without having to touch the front sight.
There are two .110" holes drilled in the Carry handle that has been match color filled. These holes were drilled for a repeatable scope mount. As you can see in the picture, they are not very noticable and can be re used in the future. I just wanted to mention it. This is the common small pin. Shipping is extra.