Hit the hardware stores. There are all shapes and sizes of nylon washers, spacers, bushings, and sleeves for sale in the hardware bins. Take a real one with you to compare with, or even better, take a joystick assembly and some tools- that way you KNOW it fits. You might have to hit more than one store- I went looking for some parts to fix some incomplete sticks and it took 3 stores before I found everything I needed.