Well, now I'm going to answer my own question (LOL)! I did a little Googling and came up with an answer. It appears that the entire gauge section doesn't print on the pattern, for whatever reason (strange). But, here it is:
GAUGE: 12 sts = 4” (10 cm) in St st; 19 1/4 sts and 14 2/3 rows = 4” (10 cm) over plaited cable pattern using larger needles
Now, THAT makes total sense! Guess I was pretty much on the right track with my assumptions. Good to know my logic hasn't completely left me yet....!