Mshootnit, I was shocked that it ONLY brought 38,000 dollars. The Army (Springfield Armory) built approximately 50,000 Gas trap Garands, with three distinct types. They were all recalled and re-built in the days before WWII. The Army was devastatingly efficient in getting nearly ALL of them to be rebuilt to Gas Port configuration.
Today there are about 50 gas trap Garands known to exist, with perhaps a handful more out there undiscovered. Most are in museums. The RIA museum has two, the Springfield Armory National Historic Site has a few, including #1. RIA has #2. They also have Rock Island Arsenal U.S. Rifle, model 1903, #1 in original rod bayonet configuration.
Private collectors have a handful of Gas trap rifles and the few survivors that exist could be anywhere. In your grandfather's closet...who knows.
Finding one is like finding the Holy Grail.