Essays. 1865 Prevost Essays of Paris: 10pa with black overprint, three singles including black on white paper, red on white paper and pale brown on green paper, fine and scarce (3). (Image)

1865 Prevost Essays of Paris: 10pa red, without overprint on a miniature card, fine and scarce. (Image)

1865 Prevost Essays of Paris: 10pa red, with black overprint on vignette, white envelope, fine and scarce. Note: Unlisted in the Nile Post (Image)

1865 Prevost Essays of Paris: 10pa red, without overprint & with additional 1pi overprint below vignette on a blue tinted envelope, fine and scarce position of 1pi ovpt. (Image)

1865 Prevost Essays of Paris: 10pa blue, without overprint & with additional 1pi overprint at left on a white envelope, fine and scarce. (Image)

1865 Prevost Essays of Paris: 10pa red, without overprint & with additional 1pi overprint at left on an off-white envelope, fine and scarce. (Image)

1865 Pellas Brother Essays of Genoa: 10pa bright yellow, upright watermark, imperforate single showing "10pi ovpt instead of 2pi" error, clear to large margins, very fine and rare. (Image)

1865 Pellas Brother Essays of Genoa: 20pa blue, unwatermarked, imperforate single showing "1pi ovpt instead of 20pa" error, large to very large margins, very fine and rare. Expertise: C.F. Hass. (Image)

1865 Pellas Brother Essays of Genoa: 1pi mauve, upright watermark, imperforate single showing "10pa ovpt instead of 1pi" error, large to very large margins, some stains, rare. Expertise: C.F. Hass. (Image)

1865 Pellas Brother Essays of Genoa: 1pi mauve, upright watermark, imperforate single showing "10pa ovpt instead of 1pi" error, large to very large margins, very fine and rare. (Image)

1865 Pellas Brother Essays of Genoa: 5pi blue, unwatermarked, imperforate single showing "1pi ovpt instead of 5pi" error, large to very large margins, very fine and rare. Expertise: Signed C.F. Hass. (Image)

1865 Pellas Brother Essays of Genoa: 10pi blue, unwatermarked, imperforate single showing "1pi ovpt instead of 10pi" error, large to very large margins, very fine and rare. Expertise: Signed C.F. Hass. (Image)