It doesn't seem that the grille holding system has changes much over the years.
On the 83 there is a rubber snub that fits in the upper channel where the hood latch is.
See photos below
I think what usually happens is there are a pain to get of, so when the grille is removed, it is broken and then the grille is replace without that part.
I did not want to break it removing the grille, but I hope you see what I mean, if not drop on by.
Yesterday I had to replace the plastic and rubber crap that goes on the seat bottom for an easy glide in the track, would you know they are 2 different ones per seat and good luck finding them new!!!