In the photos I've completed the ties and stringer structure. You can see the template lines underneath. Note I'm off kilter with those stringers. The ones on the left side, I realized I need not cut all the way through. I cut 1/2 way by hand with my razor saw, then "snapped" the joint which resulted in perfect butt-end alignments, and a time saver for sure. But I should have kept an eye on the ends.
Once all was dry I removed the paper template and cleaned up the part with a wire wheel in a discount moto tool. Kudos to Mr. Frary for his 101 tips (now 202 and 303 tips!).
I removed the plastic ties from the code 83 ME rail along the curve where the trestle will go. The stringer/ties structure fit nicely under the bare rails.
When fitting the parts to the site on the layout, I will be alternating between installing bridge structure and completing scenery in order to avoid a "trestle trap" that could prevent easy provision of scenery details.