I think the Originals from Boutique stores are full grain, I have a couple turn lock belt bags, the leather is nice , thinner than vintage bag leather but definitely full grain, attention to details is better too, also most 1941 newer bags are full grain too.
Now outlet start to promote their version of Originals. Only say natural pebble leather, judge by photos , they are less quality.
ETA:
@houseof999 knows 1941 bags well, hope she will give us her expert opinion . The several 1941 bags I got all are full grain.