From what I understand SOCOM Mfg. sold out to another company. VHM (spelling?) is making the uppers ideantical to the Socom side charging handle upper but when I inquired the vendor did not know if they would be producing the lower as well.
I have two uppers and lowers built into complete rifles, they are sweet! Good luck in your search and if I can find anything out on who might be producing these now I will let you know.