Actually, you should really look into the 1970-S and the 1972-S you have there. There are two varieties and an error as well you should look for. One is the "Double Die Obverse". A very nice item to collect. I can't see from the picture but if you take a picture of them by themselves, we might see better.
The other is that there is two different dates for 1970-S dates. A "small date (with high 7)" and a "large date (low 7)". If you have the small date with high 7, you can have a $100.00+ coin alone. So look closely with a loupe or a microscope. Study the differences from online.
Small Date Variety:
The Small Date variety is also known as the "High 7" variety. Even though "Small Date" is the more generally accepted term, it is easier to distinguish the two varieties by focusing on the location of the 7 than the size of the date itself. On the Small Date variety, the top of the 7 is even with the top of the 9 and 0 adjacent to it in the date. A second diagnostic for the Small Date variety is a weak LIBERTY which actually appears "mushy".
Large Date Variety:
On the Large Date variety, the numeral 7 in the date is noticeably lower than the adjacent 9 and 0 in the date. On the large date cents, the word LIBERTY is much stronger than on the Small date variety.