Until about 1809 Guard and Line Grenadiers wore the same Bearskin cap. Thereafter, only the Guard wore bearskins. To complicate matters, bearskins were only worn by the Old Guard Grenadiers (with front plate and red back patch) and Chasseurs (no plate or patch) The Middle and Young Guard wore shakos.

Other distinctions were that the Guard had blue collars, red turnbacks and red cuffs with no piping and a white button background. Line Grenadiers had red collars with white piping, white turnbacks, red cuffs with white piping, blue button background with red piping.

oh this helps a good deal and thank you.before 1809 from a plastic soldier point of view poses with bearskins could be both line and guarg.after bearskins only for guard.
thank you
tom