Grille badge/front motif attachment?

1971 NADA 3500S--had to replace my PAS lines, which entails removing the entire front from the car. During this process I removed the (tatty but more or less intact) front motif by gently prising a couple of u-shaped metal grabbers from the (smooth, about 0.2") posts. The operation being now complete, I need to re-affix the front motif to the bracket, but I find that the u-shaped metal grabbers no longer hold with any confidence.

So what reliable method is used to attach the motif these days??


First thing I tried. The prongs have small teeth, but they no longer bite into the mounting rods, probably blunted in the removal process.

The rods are an odd size, 0.197" or so. Too big (or small) to thread and the push-on (speed) nuts I have found so far do not fit.