I was just searching for some information on the South African song "Marching to Pretoria", and found this database of Afrikaans folk songs with really excellent midi files. I haven't yet checked, but I think they're all from the FAK Sangbundel.
Also, I found it through this discussion board, with a fascinating conversation on "Marching to Pretoria". Thanks to "Q" for the link.
Another poster, "Flatint" posted a transposition of the lyrics of a song that sounds different but has a similar title, "Marching on Pretoria", and searching for that lead me to this poster's database of rare South African recordings. This is quite an amazing archive, and represents an incredible collection.