I wish Rocky Mountain Dashes was still around.
Speedway carries a good selection, both bare and complete with gauges. A little pricey for the complete ones, but that was the case with Rocky Mountain back then, too.
https://www.speedwaymotors.com/shop/plymouth-duster-dash-panels-and-components~102-43-363-128-491
FWIW, in the mid teens Rocky Mountain made a brief comeback as "Peak Dashes", but they're gone again too. But it may help broaden your search if you're hunting for an original one.