These were sometimes used at the factory if the emblem is installed in a location where the back side is not accessible. And body shops sometimes use them instead of the OE nuts to re-install emblems if the nuts are in a hard to reach location. Installing an emblem with these clips is easy ... they just press on over the emblem studs & snap into the holes. But removal isn't always as easy ... you have to carefully pry the emblem off.
Whoops lol I just looked at my pile of emblems because this had me curious and I realized I messed up, I have one large emblem with the bowtie that has no nuts attached to it, and it's the trunk lid emblem. You can see in the picture all the adhesive still left on the studs. Mine was glued in, and it's a 73. I put the nuts back on all the others