It is unlikely (but possible) that FN has made an HBAR barrel, as they exclusively make M16A2s, A3s, and recently A4s, all of which have the A2 profile barrel.
Stamping dies are cheap, and it wouldn't take much at all to stamp a few letters on a no-name barrel to increase it's "value". I know Kurt at KKF will restamp your barrel if he has to turn down the portion that was stamped from the factory, and you wouldn't be able to tell the difference between his stamp and the factory stamp.
-Troy