Please,Please,Please DONT chop it
! Let it be and take it to a good gunsmith. Everyone above has good advice but if you realy want to get old book with your gun put an original Poly-choke on the barrel to give it the real time period look. Screw in chokes are better but poly-chokes look cooler and they do work well. Plus the extra weight is needed if barrel is cut to keep the recoil operation working properly.