Thread: Dumas Aine 32 date of manufacture date?

Acier Fondu is indeed 'cast steel'.

Check this out for cutler and knife manufacturer stamps from Thiers.

Trente-Deux 32
Dumas Ainé
Véritable Dumas

Established in 1818. The Véritable trademark was registered by Etienne Dumas. Girard Dumas filed trademarks 22, 33, 132,139, 320, 321, 322, 323, 1032, 3200, 3210 and 3211 on February 11, 1859. The company and trademarks were acquired by S.A. ROUSSELON Frères & Cie (Rousselon Brothers & Co., established in the 16th century) in 1882.

I have one of those too, but I think mine is a bit younger than yours. I have no idea about dating yours or mine beyond that , though, I haven't studied French geometrical and stylistic developments in any detail.