Funny, I just recently purchased a main drive gear and the nut for my 6500C3 that I boofed up trying to swap a power handle on it. I looked at ereplacement parts but they no longer had the nut available as it was discontinued for some reason. I ended up going through https://www.fishingreelparts.com/, a authorized dealer on the ABU site, they had both parts, good price and fast shipping, would not hesitate to order again through them if I were to need more parts. Ordered 6/23 and received it 6/26, I live in Virginia.