If you start to get far from that angle, change the end points and add more braces. Braces were bolted in place. One bolt in the center is better than multiple bolts. Allow enough extra wood at the brace ends so that the bolt won't pull out of the end. Bents are designed from the top down, that is, the bent tops are all alike, and their widths will vary with height.
High ones are wider than low ones at the bottoms.
Bents are spaced about 12' - 18' apart, depending on the load. In building a model, there is a certain wisdom to building the trestle upside down on a workbench. Use this drawing as a template to cut and assemble the pieces. The old waxed paper trick will keep you from gluing pieces to the drawing. Assemble the cap, sill, and verticals, then add the sway bracing.