(read how to identify your stamp below)
You have the 1½¢ Harding from the years 1925-30. It is a very common stamp and with very rare exceptions is worth less than a dollar whether used or unused. If, perchance, you have one of the rare exceptions the stamp will be accompanied with a certificate stating its identity. The chances of finding one of the rare examples without a certificate are about the same as being struck by lightning...twice.
The first variety (#553) was issued in 1925 and has a perforation guage of 11 all the way around. This stamp can be found by clicking here. The second variety (#633) was issued in 1927 and has a perforation perforation guage 11 at the sides and perf guage 10½ on the top and bottom. This stamp can be found by clicking here.
If you do not possess a stamp guage and are lucky to have another stamp from this same series there is another method of indentifing the number of perforations on each side. If you lay one stamp face up in front of you, on a flat surface, place the other stamp's left side next to your stamps bottom side to see if it has an exact match up of the perforations all the way down the side of that stamp. If by pointing the tips of the perforations, of each stamp, together they will touch all the way down, the perforations on that side of the stamp are perforation guage 11. If, however, the perforations do not match identically and there is a slight mismatch, then that side is a perforation 10 1/2.
The stamp has the letters Kans. overprinted on the face of the stamp
The value of this stamp (#659) can be found by clicking here.
The stamp has the letters Nebr. overprinted on the face of the stamp
The value of this stamp (#670) can be found by clicking here.
The identify this stamp one needs to ascertain if it is a Flat Plate printing or a Rotary Press printing. Referring to the illustration below you will see if that the printing of the Rotary Press stamp is slightly wider (and taller) than the Flat Plate stamp. If it is a flat plate stamp (#576) then its value can be found by clicking here. If it is a Rotary Press stamp (#631) then its value can be found by clicking here. There is little difference value between them.
The stamp has no perforations on top AND on the bottom
The stamp has no perforations on BOTH sides
To determine the difference in the perforations between #553 and #633 you will need a copy of the very common 1932 3¢ Washington (#720). A picture of which is shown below. Follow the instructions below