I have in my collection a Zulu iklwa (18 inch blade) and knobkerrie. Both have been cut shorter than they would have originally been. Both were acquired separately from different places but they both have exactly the same overall length (27 inches).
My theory is that returning soldiers shortened their war trophy souvenirs, so that they would fit into their kit bags.
This is something that has intrigued me for a some time. I have tried looking on the Internet to find information that would support this theory, but without success. Brecon Museum advise me that kit bags were not issuesd to British soldiers on active service in the Zulu War. Perhaps they were issued with kit bags for the sea journey and the march ashore to and from their base camp. Were their kit bags 27 inches long?