BobW said

I don't know the size of the pastic piece you are showing, but these work on the belt molding on my '64 Valiant. There are measurements in the ebay listing.
https://www.ebay.com/itm/25-pcs-NORS-fender-quarter-door-belt-moulding-trim-clips-fits-Chrysler-Dodge/133018937024?_trkparms=aid=1110006&algo=HOMESPLICE.SIM&ao=1&asc=20200520130048&meid=dc5c8e63e9ad4908a1e90911e8f2b0fd&pid=100005&rk=4&rkt=12&mehot=pf&sd=142833413753&itm=133018937024&pmt=1&noa=0&pg=2047675&algv=SimplAMLv5PairwiseWebWithDarwoV3BBEV2b&_trksid=p2047675.c100005.m1851
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