This book by a Regimental Officer from 1859 looks interesting.
Here's an extract from after the Alma battle which talks of the contents of Russian packs
No sooner was the British Grenadier allowed to pile arms, and "fall out," than he acted nobly—worthy of himself. He went mercifully amongst the poor moaning, bleeding Russians (remarkably fine young men, by the bye) giving them drinks of water out of his own scantily filled bottle. Having done thus charitably, the hero proceeded to look after his own interests, to make an inspection, verily, of the cow-hide knapsacks so liberally scattered about; and well pleased was he to find them comfortably furnished. Every " Rooshian kit" contained a long thin roll of black rye bread, carefully enshrined in a canvass envelope, just like a petrified black pudding—prog most uninviting to the eye—a good cotton shirt, a pair of drawers, flannel belt, hold-all, complete " housewife," and some leather for mending boots, &c. But of all the personal property lately appertaining to the enemy, their serviceable Russian leather boots took our men's fancy the most. In every direction you observed Jack, Tom, and Harry, unceremoniously, but wisely, trying on these excellent moveables, and, as soon as fitted to their liking, flinging away their own used up " bluchers."