Well spotted!
And at this point it would be a good idea if all those who swap out non-defective parts on honest milsurps that have been well-used (and thus probably at some time overhauled at an arsenal or base-workshop) in order to have "correct" parts and matching numbers, claiming that they are "Only restoring it to its original configuration", stopped and considered the ethics of what they are doing.
The example examined in this thread shows the bottom end of the slippery slope that many step on to when they start "improving" their milsurps.
"Restoring to correct original configuration" ....> Falsification....> Forgery/fake...> Fraud.