Actually I was wrong there and should have said the pivot for the ground brush doesn't have an insulator, but the spring end does, so all 3 spring ends should have an insulator with a groove for the end of the spring. See my first picture in #43. I would move the insulator from the ground post to the output post and either find or make a small insulator with a groove to hold the brush end. For the ground brush you could actually get by with nothing for the spring end, but then the spring would have less pressure on the brush. Hardware stores often have some kind of insulating tube or something that might work. Take the end plate in to show them what you need. If you can't find anything close by, I can mail you one, and hope it doesn't get lost or broken.