As MakeItHappenCaptain said, there are many variations. Nearly every model is different in some sort of way. There was only a few years when they were made when no change was made. If you are wanting to find out the differences in each model, the Cessna Pilots Association have a very comprehensive buyers guide that is essential for anyone looking to buying a C210. As to the early models, they should have a placard with all the speeds you need to know.
