The middle three positions identify this as a CR125RA which I think is a 1980 model. (The first five positions identify the type of part and the last three identify subsequent modifications. This is the first iteration, later ones might be XXXXX-XXX-710 etc.) If you go to
http://www.cmsnl.com you can download a complete list of model codes. BTW the way later models can still use the same part and the older model code will be used i.e. many parts on the 1978 through 1980 CR250R share the model code 430 because they were used on the 1978 first.