The decree from February 1805 prescribed chage from mitres to shakos, however implementation was slow due to campaign that started soon after that. Guard units and those around ST.Petersburg received shakos, however, we may assume that most of line units still wore mitres for some time. One of such units was Pavlovsky Grenadiers, who wore mitres in 1805-1807 campaigns. The unit distinguished during 1806-07 campaigns and in 1808 a decree was issued to reward Pavlovsky for their feats in the last war by keeping their mitres - the ones that were carried in the battle. "For outstanding courage, bravery and intrepidity, with which the regiment acted in numerous battles...to keep their current caps as they were carried out from the battlefield, although some might be damaged; let it be for ever a monument to their excellent bravery".
So, there's no direct indication - for what particular action they were awarded; it was for their behaviour in 1806-07 war in general, most outstanding actions evidently were Eylau and Friedland.
Many frontplates indeed bore bullet holes and their owners' names were engraved near lower edge of the plate.