There are two very small Kolbe units listed on this site, Gen Kolbe and Komdt Kolbe
The General's name was Willem J Kolbe [photo attached] so he is not your man.
I'm not sure what VK means, in "Kolbes VK Korps".
VK could mean "Scouts" i.e. Verkenner Korps or Verkenning Korps [as in Edwards Verkenner Korps = Edwards' Scouts] - but in the list of Scouts units [Edward's Scouts, Fichardt's Scouts, Hassell's Scouts, Jooste's Scouts, Kirsten's Scouts, Ricchiardi's Scouts, Runck's Scouts, Scheeper's Scouts, Theron's Scouts, Theunissen's Scouts, Von Goeben's Scouts], I can find no Kolbe's Scouts.
So, VK could mean Veldkornet.
Sorry if that is no use at all!
The past is not dead. In fact, it's not even past.
I am wondering whether Frederick Fortunatus Kolbe was a relative of General Kolbe
His rank on medals is " Kapt .':
His DTD was for Heiwand ,Spioenkop 25-1-19oo ( wounded twice ) and Jaline 24-9-1901 ( wounded )
Served at battles of Colenso , Sp ??? Ko??? ( this probably Spioen Kop ), ??? 23-2-1902 ( writing on form difficult to read )
Served under Botha, Botha, Beyers , Opperman and ( illegible )
It may be my ignorance, but: I've not heard of Heiwand nor Jaline, as places or battles.
If you too can't place those names, perhaps you could upload a copy of the DTD/Vorm B etc - just in case the handwriting can be interpreted differently?