The story of the Grenadiers of the 28th wearing French packs comes from the Regimental history 'Narrative of the Campaigns of the Twenty-eighth Regiment' p. 241-242

https://books.google.ca/books?id=oYNIAAAAYAAJ&printsec=frontcover&dq=28th+foot+regiment&hl=en&sa=X&ved=0ahUKEwiI0tvwoLDhAhUywlkKHfaACaUQ6AEIRTAF#v=onepage&q&f=false

Cliff

Thanks Cliff- I missed that, on the very next page.

Here is the relevant passage from Cadell:

"The Emperor Alexander paid particular attention to the 28th, and admired much the grenadier company. He was much pleased with our brown calf-skin packs, and after minutely examining one, asked their origin. He laughed much when I told him that they were found in a French store we took in Egypt."

So they were a good quality calf-skin- unless they found enough packfor replacements taken from store down the years. However, they were not a distinction as far as we can tell, merely loot. It doesn't seem clear whether it was just the grenadier company or the whole battalion. Cadell, having been a grenadier subaltern in Egypt, was by 1815 acting C.O.

(His book is a lively and vivid account of service in the Peninsula and Waterloo campaigns, which I would reccommend.)