IDENTIFYING THIS STAMP
This is the 12¢ Washington. Both the above are desirable to own, particularly the one on the left.
The stamp on the left is without perforations and was first issued in 1851, its value can be found by clicking here. The stamp on the left was replaced by the stamp on the right, which has perforations, its value can be found by clicking here.
VALUING THE STAMP
With the stamp without perforations (imperforate), the value is quite dependent on how well it was cut. If you see the design clear of the edges on all four sides then you have a more valuable stamp. If, on the other hand the stamp was cut a third of the way into the design, the value will be less.
THE RARE REPRINTS
This stamp was reprinted (shown above) on hard white paper in 1875 and it can be found by clicking here. The odds of finding one are very slim and they require a certificate to verify its identity.