I've had my current bike (2001 CR250R) for a couple of years now and decided to get the right springs and refresh the shocks and forks. I've done the forks a couple of times so I figured the shock would be about the same. I ordered the Pivot Works shock rebuild kit (PWSHR-H05-000) to do the job. I got everything apart fine. Unfortunately I cut the old piston band to get it off. Of course the new one is a different size, should have checked that first I guess . I also noticed that the new shaft nut is different. The original is a typical bolt but the new one is a castle nut. So two questions. Is it OK to use the castle nut or should I and can I reuse the original? I've read that you need a new one and if so where do I get that? Second. What's up with the piston band? The previous owner had the shock rebuilt professionally, I can tell because it had the build sticker on it. All of the writing is worn off so I can't get any details about what was done. Maybe I have an aftermarket piston? Any help would be appreciated.