I see that those Duchy of Warsaw (not Vistula Legion) regiments (4th, 7th, 9th), that served in the Peninsula are often stated to have worn French uniform. (One source does hoever say that the 7th retained Polish uniform throughout, so there is a contradiction here).
Given that an observers comments or sketches only represent a snapshot in time, I wonder how true is this?
Were they equipped from the start in French uniform? Or did they go to the Peninsula in Polish uniform, which then wore out and was replaced from French stores?