Actually Eric, the card featured in your Trader Speaks article is from the 1917 D350-2 Standard Biscuit set, identified by the card numbering on the front and the reference to 200 subjects on the back (not 80). The second scanned card in Leon's first post shows an example.
I'm not offering excuses but for whatever reason the grading card companies have had problems with these sets for a long time. Leon's first posted example is a mislabeled SGC card, and below that I show mislabeled cards from both PSA and GAI. Again, it shouldn't be that hard to tell the two sets apart--look for card numbering on the front and the number comprising the set on the back.
Also, the hash marks or ticks that frame the ad message on the back are designed differently. In D350-2, they are uniform strokes or bars of the same width and length, kind of like teeth in a comb. In D350-3 these strokes have wider spacing and are not uniformly sized but instead are placed in a broad-thin-thin, broad-thin-thin pattern--very distinct to the eye. These possible fakes tend to blur the two sets--trying to hit the right pattern for D350-3 but looking more like the other set because of uneven inking. They therefore may look somewhat familiar to the graders, who already have trouble telling the two sets apart.
