Sc 1731 Carl Sandburg & 1770 Robert F Kennedy. 13 & 15 Cent stamps From 1977 & 1979. Two Great PB's of 4.  Never Folded, No Perf. Separation. MNH. These Can Be Album Mounted  and Collected Without Issues. Or  Perfect  For Mixing Up Your Postage for Mailing. Have Fun With Stamps. Enjoy More Savings With Reduced Shipping Costs When You Buy More Than One Item In The Same Order. Note: The Stamps You See Are The Stamps You Will Receive, Count On That. Thanks For Looking!