: Here are a couple of pictures of the backband and the cockpit.

That's pretty clear (but I couldn't get the second pic to work last night).

Anyway, instead of bolting the straps into anything, what do you think of using those vinyl canoe patches? They must be around 3" in diameter and have a d-ring for attaching strapping. They could be epoxied (or vinyl glued) to the hull behind the cheek plates... (And they're really easy to make yourself for next to nothing!)