An adventure/mystery book from the 80's I think. The hero was in Africa and he shot his girlfriend accidentlly as they were hunting. A snake attacked her and she stood up to get away from the snake right when he was shooting. His brother had to knock him out. The safari leader had lost an eye years ago and had a series of eye patches he would wear, that his girlfriend had painted eyes on. He was incidental to the story, but a great character. The code names of the spys or drug dealers (can't quite remember what they were) were Needle, Stitch, Hem and Scissor.

Not sure if the two brothers actually worked for a spy agency or they were just sucked into a mystery along the way and were determined to solve it...