Bed trim attachment
 

Doing some work around taillights and realized there are no fasteners holding on rear trim pieces. Seem pretty secure, but would hate to lose one on the road.
There is a threaded post coming off the back of the trim. Wondering what was originally used to attach it...if it was something beyond a bolt since it's on a curved surface.
1959 Chevy Apache Fleetside

Re: Bed trim attachment
 

There should be a threaded stud top and bottom that a nut threads on to tighten. Also, there is a metal strip that spans the two studs that goes on inside, under the nuts.
The trim end is held on with screws.