Part Number, they are not serialized.Is 7267064 a part # or the Serial Number? Mine has the same number so I think it's the part #.
Interesting side note:
The first design was a three piece design: the handle, a tube and a tube cap, similar to the M1 operating rod. However, during testing, they never found a satisfactory method of attaching the cap to the tube, so they went with a solid bar and bored a hole in it to make a integral cap.