As far as I know, a Cap is just the name of the plane, the number afterwards is the model type such as a Cap21 Cap232 Cap580, (there was never a Cap260, that is actually an Extra 260)

The 27% is a scale size. so if you look at the measurements of the real one and the model, the model should be roughly 27% the size of the real thing

Since you posted this in the beginners forum, I have to ask, You do understand that a Cap is not a beginners plane, They are more like your third plane.