'65 Barracuda Grille Fasteners?

Trying to finish up the front grille today. Need to find what type of fastener is used alongside the missing rubber bumpers (if I remember correctly the bumpers are round about the size of a quarter). In the photo one can see the hole which matches up the front parking light frame with the center grille. Just can't picture which fasteners went there or if there was a nut or speed nut. Thank you.

P.S. I know, I know, the panel behind the parking light frame should be blacked out (is going to be white for the time being).

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