If you want a bunch of rockets in different sizes, check out ancient or medieval Chinese armies. I have seen rockets & fire lances listed with some of them in my looking over lists. It would be really simple to make them though. Get a variety of small tube & toothpicks, wire, or even plastic broom bristles. Cut the tube to lenght, then glue the stick in & cut to what ever size. Scratch builds will give you that irregular look. You could even slip a piece of thread in when you glue the stick in the tube for a fuse.