Hi Eve,
This a good book to learn about gussets.
http://www.leathercourses.co.uk/the-leatherworking-handbook/
As well as the three Al Stohlman case making books.
Good luck,
Steve
It means there's way less than 15 to 20.
few (fy)adj. few·er, few·est 1. Amounting to or consisting of a small number: one of my few bad habits.2. Being more than one but indefinitely small in number: bowled a few strings.n. (used with a pl. verb)1. An indefinitely small number of persons or things: A few of the books have torn jackets.