Do you think the Didatto set might be as valuable as the Chavet set, although I'm going off-topic with this.
No, it was a budget/mainstream set. The company itself, it's a toy manufacturer that sells various toys besides chess sets. Here in the Netherlands there was such company that also sold localized version of French set, it was called Revanche. It was also two woods set, boxwood/rosewood.

















I suspect there is a distributor/importer who used this codex. Not sure why they didn't just use the factory codex, this is one of the Chavet mystery again.