Hi Fraxinus,
I checked Windrow's Montcalm's army and you are correct. The La Reine grenadiers have blue waist coats. In Windrow's publication the grenadiers are wearing tricorn hats (see Plates D2, F3). These new figures could be used as grenadiers for the following regiments, Bearn (Plate F2), Bearn (Plate D1), Berry (F2).
I also like these frontline figures even if they are inaccurate.
Benjamin