Well, Father Steve, I can't help with the derivation of Mogambo but I can you tell you more than you may want to know about the movie.

It was originally a play by Wilson Collison, "Red Dust", set in a Saigon rubber plantation and filmed under that title in 1932 by Victor Fleming with Clark Gable and Jean Harlow.

In 1953 the original scriptwriter, John Lee Mahin, changed the location to the African veldt where it was filmed by John Ford starring, again, Clark Gable with Ava Gardner and Grace Kelly. The story was also filmed as "Congo Maisie" in 1940.

And the plot? -- take your pick:

The headquarters of a Kenyan white hunter is invaded by an American showgirl and a British archaeologist and his wife, and they all go off on a gorilla hunt. [Halliwell]

The lure of the jungle and romance get a sizzling workout in Mogambo and it's a socko package of entertainment, crammed with sexy two-fisted adventure. [Variety]

Interestingly, it was released without a music score, just 'jungle sounds and native rhythms".