U.S. & Worldwide Stamps & Postal History

1860 10c yellow buff, stone B, block of four, unused with original gum, positions 2-3 / 12-13, including position 12, which was the inverted position in the stone B and subsequently substituted in this second stone; also showing "20" instead of "10" below the shield in position 3, being a variety which had not been reported before 2013, and with at most only five examples recorded; (stated by the late Dieter Bortfeldt to be a retouch), ex-Goeggel, with Bortfeldt certificate ("This can now be classified as one of the great items of classic Colombian Philately. Having checked a wide range of reference material available, we can state that no more that 3 stamps unused and in blocks exist")
Estimate: $1000