Splintered A is: Anchor Harvey
Key Hole is: Cerro Forge and FNMI / Cerro Forge
is: Cardinal Forge
M "diamond" is: Mueller Industries
Offset Square is: Brass Aluminum Forging
Crosshairs w/"AR" is: ArmaLite
LMT is: marked LMT or L is: LMT
AF is: Alcoa Forge
LM is:C AF is: Colt Alco Forge
C MB is: Colt / Mueller Brass
CH is: Colt Harvey Aluminum
CK is: Colt / Kaiser Aluminum
CM is: Colt / Martin Marietta
D is: Diemaco
DK is: Diemaco / Kaiser Aluminum
E is: Emco
EK is: EMCO/Kaiser
E MB is: EMCO/Mueller Brass
FA is: FNMI / Anchor Harvey
FK is: FNMI / Kaiser Aluminum
FM is: FN/Martin Marietta
FMB is: FNMI / Mueller Brass
K is: Kaiser Aluminum
LK is: LAR / Kaiser Aluminum
LM is: LAR / Martin Marietta
LM is: Lockheed Martin *Newer Ones 15 years or Younger*
PA is: Capco / Anchor Harvey
PM is: Capco / Martin Marietta