Vinyl tip trim fasteners

I got a set from RT Specialties, but I am unclear how the side pieces attach. The fasteners he sent are too big for those holes, besides I don't think you can access those holes from behind to attach the speed nuts.

I believe the fasteners I got are for the trim that goes on the Dutchman panel, however there are two small holes on either side of the middle hole that are smaller also. Man I'm so confused.

Here are some pictures. 70 Dart.