the wood buck for a Bugatti design "MATRICE DE PIÈCE DE FONDERIE OU 'MOULE MÈRE'" translated is roughly, foundry piece matrix mold

https://www.christies.com.cn/lot/bugatti-matrice-de-piece-de-fonderie-ou-5888805/?intobjectid=5888805&lid=1

https://www.bugattipage.com/2015news.htm