Sorry to be the bearer of bad tidings, but, whoever "verified" the serial number, was being untruthful with you, either from ignorance or malice.

Also, even if the barrel length is right on the money at 22", SA did not install THAT front sight in THAT location - the work is nowhere close to their quality. It IS a genuine military sight base - not saying that it isn't - but SA didn't put it there.