The book calls that serial number a 30" gun. So, your barrels have been cut.

The rib matting not terminating at the end of the rib is not a definitive way to tell if barrels have been cut on Parkers, but it sure is a red flag.

VH grade and above ended and had a straight had cut line at the end. Trojan grade guns just plain ended and sometimes not evenly. Or they could run off or come close to it.

B.Dudley