A Most Unusual Zulu Spear

[drac2k]

At first glance, one would think that there wasn't anything special about this spear; maybe even subpar, as the lance made such a forceful impact that it drove the spearhead further into the shaft, causing it to split much as a wedge would act upon a piece of gum or that the lance has been cut down to 40".
The spear becomes special when one looks at the logo on the spearhead "W.MARPLES& SONS," which was a tool manufacturer in Sheffield England for over 200 years. I contacted an expert collector of these tools(yes other people collect other things than swords & knives), and he told me that logo on the spearhead dated it between 1875 & 1895. I asked him did this company ever make trade blades such as knives and spearheads and sold them for barter, much like the Hudson Bay Company and others did with the local natives; he answered that he was unaware of this being the case, but that he couldn't figure out what tool could be reshaped to make this item. The spearhead doesn't seem to have any irregularities or forging flaws or grind marks to my untrained eye that would lead me to think that it was a locally repurposed tool.
My theory comes to a grinding halt one thinks that this spearhead would have been sold to the Zulus in the heighth of their wars with England; not an act that would have been condoned by the home country. A possibility is that this is not a Zulu spear, but a Shona or other South African one, for tribes that may have aligned themselves with England against the feared conquering Zulus.
Any other theories are welcome