Ken,
I would put the bushings on the mandrel first, just to make sure they don't fit. I bought a kit that needed 8mm bushings and I have a 7mm mandrel, but they actually ended up being the type of bushings that fit on a 7mm mandrel and also fit into the 8mm brass tubes. This might have been what Jeremy was talking about, but I'd check just to make sure before you spend anymore money. :icon_thum