The price of rosette rivets has crashed. Used to be $60 for a pair. Now $2.29 a pair plus $1.57 postage from China here.

You'll need to color them black though, since they are stainless. These are 1/8" diameter, but be careful - the $9.99 ones from Amazon are 1/4" here. However, they say these are "NOS Dash Rosette Rivets Stainless Steel Fit for Ford Amc Chrysle Door Tag" with Chrysler misspelled. Not NOS. Also not black. Also won't fit dash, unless the drawing is incorrect and it's the head that's 1/4" and not the shaft.

But really, you can just make your own for free with a file in a few minutes if you don't have the factory originals. Factory original blackened aluminum rivet without the pulled steel shaft above, two home made ones below, also aluminum, blackened with magic marker, and the steel shaft. I'll be gluing the factory original heads and shafts back on my newly painted dash. Made the copies just for fun.