I believe this is the final model of the 501 66, the late-stage version, or possibly the early red-ear version. The button back is number 6, and the shrinkage rate is 10%. It's an original from October 1980. Recommended for slim men or women who love vintage clothing. Please refer to photos 12, 13, and 14 for the size. There is no noticeable damage. The paper patch is missing. For those who understand vintage clothing, thank you. Please contact me if you would like additional photos. This is the final price reduction.