Sourcing high grade silex stones for flintlocks

Helping a fellow national shooter, M. Cruz, sourcing high grade silex stones for his new MLAIC competition muzzleloader flintlock pistol, a Arsa, made in Spain, .45 caliber, "Manton" model, I came across the recommendation from this Spanish manufacturer for F. Javelot (France). The Arsa Manton pistol uses 5/8 " stones (15 x 18 mm) such as the one shown on the photo on the left.

Specs and price list by F. Javelot for flint stones - 2011

Additional research also pointed another strong recommendation towards the "old school guru" of flint stones - highly rated within the demanding MLAIC competition shooter community, Jean-Jacques Dutrieux (France) . The similitude between the tables, and the common French nationality, make me believe that F. Javelot is a dealer for Dutrieux products.