The tool was DEFINITELY NOT invented by Henry Bouchard. See Denis Diderot, Jean D'Alembert: L'encyclopédie de Diderot et d'Alembert, ou dictionnaire raisonné des sciences, des arts et des métiers. Paris, 1751-80. On Plate XIII "Outils de Marbrerie", you find fig. 12 and 14, with dicription "boucharde".

Best regards, PUNG. See also German Wiki.