Hi, I have just bought a set of T100s and worried they may be fake? They feel and look real but the serial number is etched into the hosel of each of the Irons 4-P. I read online it usually is only on one or 2 of the irons but this was for a different model of Titelist irons. Can anyone tell me if its the case with all Titelist irons and if my irons are real?