Not so much with the 79's but heck you can check em if you want you might be surprized what you might find.The 80 cents you will look for Seperation lines on the 1980 most noticeable on the date and liberty. Also on The 1980 D a light but previously punched S mint mark NE of the D between the date and mintmark.....infomation from Strike it Rich with pocket change and
CherryPickers Guide to rare die varieties volume 1.