You can actually see how many of the gears you need by checking the file names.
All names have numbers. "Tray 1-3" = Three of that tray, "Tray 4-6" = Three of that tray, "Tray 7" = One of that, "Tray 8" = One of that and so on. Then it's kind of easy to figure it out. I don't have any list, and I did not name the gears so it's a little hard to describe... :)