This is the only weapon in my colledtion I have no idea about what manufacturer it was made by. Probably sitting here for more than a year already, but I might be finally finished with this project. Only the mag could be subjected to change one day, so it looks like in the pic below.
With mine I attached a rail taken from the SS081 Mk46 MG I once destroyed in the process of modding.
I also forced the SIG rifle open, which consists of two molded sides and got lucky that nothing broke or got damaged. This way I custom built a rail/mechanism inside the gun to have a working charging handle. It’s not going backwards all the way like the real counterpart, however that would have required me to cut out the fine black line which is located left and on the same height of the handle/knob of the charging handle and replace it with some rubber like material.
For the moment, the Lancer L5 mag from ES provides the best fit and look.