a private (fixed wing, single engine) tour around New Guinea.
Don't!
The three previous Posters also gave good advice. And IMHO, in rising order of importance.
Going armed does however have its downpoints! If you go armed, you must be prepared to use those arms if necessary. Because if you are not prepared to do so and hesitate, those arms will be very likely taken off you, with extreme violence at that, and used against you!
Well, that is how it was about 25 years ago anyway...