To be brazed. The four cross “pins” will hold the sides parallel each other and square to the sole (they have been machined to the same width as the sole). The two front cross pins will also be used to hold the bun in place as well as support the sides. Since the rear infill “floats” on the frog and isn’t attached to the sides, I filled in those pin holes (check previous entries to see if you can see where they aren’t anymore). In a “oh, what the hell” design decision, the screw cap and front pins will have visible screws. And since the plane won’t be used on its side (on a shooting board), the screws are not flush with the sides.