1967-72 10 different Registered Rates on Cover w/ Centennials

1967-72 10 different Registered Rates on Cover w/ Centennials

A group of ten covers with rates as follows:

1. 35c + 4c drop letter rate  March 7, 1967
2. 35c + 5c domestic letter rate  May 7, 1967
3. 50c +4c drop letter rate Aug 10, 1967
4. 50c + 5c domestic letter rate Oct 31, 1968
5. 50c + 6c domstic letter rate Dec 19, 1969
6. 50c + 7c domestic letter rate Sept 27, 1971
7. 50c +8c domestic letter rate Jan 8, 1972
8. 50c + 10c airmail to U.S.A. Nov 15, 1971
9. 50c + 6c + 4c to 2 ounces domestic letter rate Oct 3, 1969
10. 50c + 6c +6c to 2 ounces domestic letter rate  Feb 2, 1971 overpaid by 2c

Half on #10 and the rest on smaller covers. Some staple holes but overall good condition and an interesting group of rates in a short period of time.