Bedrail exposed?

What does the bedrail look like under the plastic cap? Anyone have pictures? I've pried up a couple of places and looked up under fender skirts, but would be good to have a picture/dimensioned drawing. I'm looking to do a custom thing and need some solid metal, if possible, for sheet metal screws or backing plates.

 

Sorry I dont have a complete picture but this is the small portion I do have up against the cab. For the most part, the bed rail has numerous holes along the way to clip in the plastic liner.

 

BTW: It may be a little tough to get backing plates underneath the liner. I had that^^ huge whole to squeeze a nut onto a screw and that was a beyatch alone.