Hi Vandoo,
Better keep hoping, 'cause I don't have an example. Well...
Actually, if you google "carver's mallet," you'll see a modern example of a round-headed wooden mallet. They're less common these days, but there are still modern examples.
Queequeg is probably right about the arrangement of lead on the staff.
My guess is that these mallets were something like a morning star/godentag. According to the
Wikipedia article on morning stars these were basically arsenal weapons used to arm the people of a city in case of war. They were cheap, basically upgraded quarterstaves. Kind of like what we're talking about here.
I've never seen lead clading on a staff, but I have seen medieval pictures of travelers carrying weighted staffs, so it's not too unusual. Loading a staff with points, hidden blades, or hidden weights is a widespread phenomenon. On occasion, I've been sad that we can't legally do that in these modern days.
My 0.000002 cents,
F