There are several different fasteners used in the grille and associated parts, as shown here: Fasteners & Illustrations/Front Clip/
Radiator & Grille. And if you click on the blue box around one of the part numbers you'll be taken to a page that shows the fastener as well as a source, where I could find one.
The interior panel fasteners don't have quite that fancy of a page: Interior/Doors/
Door Panels. The panels themselves are held on by the "push pins" as Ford called them, and there's a source for those in there. But I don't have a picture nor source for the N800486. Perhaps someone else does?
Gary, AKA "Gary fellow":
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Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI