On old original rifles, most of the time there's nothing in the box. Just empty.
But, sometimes, what I've found, seen or been shown are some rolled up patch material and some balls, some pre-cut patches and some balls, a couple times a jag or worm, and more than anything, some sort of grease obviously used as a lube.
I've never found a bullet mold, ball block, flints or tools in there.
Of course after all this time, it's impossible to say what was there originally, or put there recently. Except the grease, I think most of the grease I've seen is original to time of use. Maybe....
The picture below is a friends rifle;
John