Let me say first that the multiple noses I made didn't work. I spent many hours and lots of money and ended up not using any of it, and it was incredibly frustrating.
I am still convinced though that I was on the right track, so I will start by telling you what I did and the lessons I learned along the way, in case you ever are in a position to make your own nose.
After creating my posterboard prototype I set about looking for something stronger to make the final product out of. The best option I found was a telescoping light saber toy. As I sliced the toys, I learned several important lessons.
-Because I had to work with the cuts that already existed between pieces it was pretty much impossible for the nose segments to be uniform.
-Every step had to be done in order, no short cuts. First, sand all the pieces so that the plastic takes paint, then paint the pieces, then sand them again so that the finish is smooth. Then cut each piece to length starting at the tip. I also melted the wider end of each piece and curved it inward so that each piece would catch the one before it as the nose collapsed.
The difference between fitting smoothly and not fitting was so tiny that even a thin layer of paint could throw things off and force you to redo everything.
This is how the plastic noses turned out when they were installed on the mask.