I tried to photograph the "Welsh heel" on the socks I was talking about:



They're knit following the "Lichen ribbed sock" pattern at the beginning of "Vintage Knitted Socks" (it's easy to overlook those couple of simple ribbed-sock patterns there in the front of the book for the flashier ones like the Gentleman's Shooting Sock, but the simple ribbed socks are nice patterns - they're plainer, but they're the kind of patterns that also work with a busy variegated or self-patterning yarn).

Right between the pale green and the pink area on the underside of the heel, you might be able to see the holes that the yarnovers form.

Here's another shot, from a different perspective:



You might be able to see the four decrease points (one at each edge and one on either side of the center stitch - which, like so many stitches in this book, is purled. Not sure I'm down wit' that. I know, I know, you can change patterns at will and I think the next time I make this one, I will. There's just something odd about that center purled stitch. I suppose it's a "vintage" detail, that many of the socks originally had it, and I suppose it's helpful for knowing where the round starts and ends while working in the round, and for knowing the midpoint of the heel when you're turning the heel...but it just looks weird to me.)