Though not the ideal Boer War era version that some are seeking, the chantey version of this, in Stan Hugill's SHANTIES FROM THE SEVEN SEAS (1961) may also have some age on it. He does not say where he learned it from, unfortunately. For what it's worth, here are the lyrics to his version:

Oh, kiss yer gal, say goodbye
CH: An' make fast the dinghy, an' make fast the dinghy, an' make fast the dinghy
Kiss yer gal, say goodbye
CH: An' make fast the dinghy, make fast the dinghy, make fast the dinghy
GRAND CH: We are marchin' to Pretoria, oh gloria, Victoria!
We are marching to Pretoria, Victoria rules the waves!

The Afrikaans part in the original verse, says Hugill, "went something like this":(!)

Mitchen truss, mitchen truss an
Da der di ding-dong! Da der di ding-dong!
Da der di dong-dong!

And he says that in the "original song," the part filled by "oh gloria, Victoria" here had Zulu words: "Ai-oria, ai kona!"