Hi Bernard,
My apologies for writing again…but I’ve struck gold! Found this little nugget on Wikipedia:
From the picture description, it appears the ‘line infantry grenadier’ regiment (soldier on left) was still in existence some time after the establishment of the Old Guard. This fellow does have white spatz, however, differing from the full trouser appearance in Napoleon:TW. Perhaps spatz were removed at certain times, or differed according to the preference of each grenadier? Out of interest, the soldier on right is distinguished by yellow epaulettes and yellow/white pom of the ‘voltigeur’ light infantry..
Thanks for your patience!
Robert Douglas.