There are conflicting accounts of what Covington did in Rhodesia. He says that he was a combat-soldier. Brother Benjamin says that to the best of his knowledge, Harold Covington was a file-clerk in Rhodesia:
In different blogs and writings, he was always bragging, "Oh, I was a mercenary in Rhodesia and I went out and did all this fighting." But to the best of my knowledge, according to the letters he wrote to my parents, he was a file clerk. He certainly never fired a shot in anger.
Lest anyone get indignant about the SPLC being used as a source on Covington, bear in mind that Covington's A Brief History of the White Nationalist Movement uses the SPLC as a source in at least three sections, quite extensively in the section on David Duke. The lengthy utterances of Benjamin Covington are directly quoted in the piece; it is not the SPLC's interpretation.