I used the Lionel trestles from the 50s-60s.
I used a Dremel tool to drill through the wooden ties to attach the track (via screws), into the predrilled metal plates that slide into the tops of the trestles.
To decrease the steepness of the grade, I used two sets of trestles. For every two sections of track I would use the next highest trestle. For the middle of the two tracks, I would use the same trestle size, but shim it slightly.
This made for an easier grade and it works great.
The trackwork is very sturdy.
