I am not very familiar with the show Trigun or the character Vash, but when I saw this revolver model I fell in love. It has many movable parts, and while it was a pain to put together and took a while, it was WELL worth it towards the end.
Here are some pictures:
Here is the link to the template and instructions:
The instructions are not very detailed (they are just pictures), and the pieces are not very well made. Also, there is no color, I colored the pieces in with a marker to make it look a little more realistic, but it's paper, what do you expect?