I know that I should not make WAGs! Howsomever, Since I have made jewelery and assorted thin wall product prototypes for the hardware and badge markets, I will say that the thin scales were formed by using a rubber block and a hydraulic press forcing the metal preform ( an approximate 3D curved sheet metal shape) into the metal molds which were used to make the composition and celluloid scales of the same pattern. For example, see the back razor's scales; that pattern is common for the celluloid scales from the 1890s onward. The annealed metal actually becomes hard during the forming process.
Your guess may be better but...
Respectfully
~Richard
Hydroforming was another technique which may have been used with the same result from the same mold.