USGI will have part number and makers stamp on web of op-rod.
7267064 TRW, 7267064 HRA, 7267064 SA,
7267064
61188
7267064
MFR 24411
USGI SA op-rod will have part number followed by SA all on one line, SAI op-rod will have part number with SA below it(2 lines).
Chinese not marked at all.
PS 61188 is cage code for Winchester, 24411 is Mercury Tool & DIE.