It turns out that I can try eating my flatbreads with skyr, the yogurt-like Scandinavian cheese, after all.
I was re-reading a recent Compleat Anachronist, which was about skyr and mysa and the evidence for Viking era use of both, when I noted that the author reports that the supermarket chain called Whole Foods imports skyr from Iceland.
There's a Whole Foods market about 20 minutes away from here by car.
So tomorrow, I will buy some skyr for my flatbread. I am very curious to find out what it tastes like.
EDIT: I did buy some skyr last night. I haven't had any flatbread since then, but I tried the blueberry and strawberry flavors (I'm saving a tub of the unflavored skyr to try on the flatbread.) Overall, I liked it. Skyr turns out to be more sour than yogurt (or at least the commercial variety is), and stiffer in texture. The fruit flavorings added to the batches I tried were less pronounced than they tend to be in yogurt. However, I like sour flavors, so that didn't bother me.