Matakishi has written The Natives Are Restless Tonight, a set of free wargaming siege rules for any game involving a large band of natives, and a small, but stalwart group of westerners. They would work for any game in the colonial era, including the Zulu War, Boxer Rebellion, Foreign Legion, North West Frontier and Indian Mutiny.
The rules use a card activation system, and involve rolling handfulls d6s. Casualties are determined by summing the attack dice and removing a figure for every multiple of 6, 9 or 12, depending upon the defensive situation.