They look like simple pyramidal / circular studs/rivets, which seem pretty common. Between these:
0.99US $ 30% OFF|100pcs Round Pointed 4 Claw Spike Studs 6mm 12mm Bead Rivet For Garment Shoes Bag Apparel Leather Craft DIY Sewing Accessory|Garment Rivets| - AliExpressSmarter Shopping, Better Living! Aliexpress.comwww.aliexpress.com
Description: Condition: 100% Brand New Material: Iron Size: 4mm,5mm,6mm,7mm,8mm,9mm,10mm,12mm,15mm(4 Claw) 35mm(2 Claw) Color: Gold, Silver, Copper, Gun Black, Mix color (4 Color in average) Size like picture. Manual measurement, there is error about 0.5-1mm. If you need other Quantity pleasewww.etsy.com
you'd probably be most of the way there - just need to figure the dimensions and get everything lined up...
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