The dovetail “pins” on the sole are square, not angled, as the sole was cut with a water jet, a 2D/axis, not 3D, process. But very accurately cut so I decided to go old school remove the excess bits of metal with hacksaw and file (rather than on the mill). Just like wood: mark, cut, pare and fit. I clamped a side plate to the sole and scribed the angles, then scribed the verticals with a square. One hacksaw cut removes the bulk of the waste, then some filing to the lines. A safe edge (no teeth) on the file allows me to file the edges without cutting into the bottom. The triangular file is used to clean up the corners and put relief cuts on all the edges you can’t see when the planes is assembled.
Once the initial paring is done, I fit one of the end tails (the other end of the side plate is up in the air). Then lower the side until the next tail contacts the sole and fit it. Repeat across the sole. You can use a Sharpie to color the pins so you can see where the high spots are (the ink gets rubbed off).