The terms "National Match" have changed over the years. Prior to the availability of rear lugged receivers on the "Super Match", the National Match was the competition rifle used in Highpower rifle. A National Match had the heavy Douglas barrel, a unitizied gas cylinder, tuned trigger, reamed flash suppessor, a heavy stock, NM sights, and was glass bedded.
I have glass bedded Garands, the M1a is similiar, it is labor intensive and a pain. It is also necessary for the best accuracy. I recommend Devcon Stainless Steel filled putty or Bisonite as bedding materials.
When the Super Match came around, about 1993, a rear lug was added to the receiver.
I talked to Glen Nelson in Georgia, he used to build the Springfield Armory National Match and Super Match rifles. He claimed his stocks were the "heavy" stocks on these rifles, but when I ordered one of the heavy stocks from him, it was slightly different in the pistol grip region from the SA stocks.
As for a heavy operating rod, never seen one. All my National Match and Super Match rifles use standard GI operating rods. They do have a heavy operating rod spring guide. Maybe that is what the poster was thinking.