I am eternally grateful to all the dedicated people who dug up and digitized all the FSI courses of the previous decades. In contrast to the hasty jobs being done these days (e.g. teach yourself Swahili) the 1968 course is very detailed and provides lots of much-needed practice on audio and in writing with respect to the noun classes and the other unusual aspects of this language. Some may argue that the old drills tended to be boring, but if you sit through them and take the time, they pay off in a big way. And the explicit translations provided end up saving learners a lot of time compared to the guesswork that passes for language learning these days.
Some material is fun to see from a historical perspective. Without being obvious, the course was teaching the diplomats of the time to communicate with their servants. The grass needs cutting in the yard, european children get sunburned, you should not let them run around, etc. There is actual safari hunting, where someone plans to go and kill elephants, rhinoceros, etc, and what to do when you hunt them. There are many words for fetching water and cutting firewood, about bad roads and bridges that give way and drop the cars in the rivers, many words about agriculture. It was a time when African language knowledge was crucial. (Now everyone there wants to practice their English.)
In addition to the monumental 1968 course, the website soyouwantolearnalanguage.com has several others, particularly where it says "off site" There is another audio course there, a 1963 alternative course, and many other little-known treasures.