BEWARE: #35's are often misrepresented as the other 1857 varieties (#31, 32, 33, 34) as well as the imperfs of 1851 (#'s 13, 14, 15, 16), either out of ignorance or fraudulently. If the cancel covers some of the attributes, like the missing pearls, it can be difficult to tell at first glance. Sometimes additional cancels are deliberately added to cover the identifying details. The bottom frame lines are sometimes drawn in by hand, as are the missing design attributes on the sides. The large side margins can be reperfed away, or clipped off to make them look like the smaller margins on the other varieties, or even to remove perf flaws, edge tears, and straight edges. An extreme degree of caution should be exercised when purchasing any of the 1851-57 series, not just the 10ct green, because of the possibility of alteration or misidentification.

Additionally, pen, or manuscript, cancels reduce the Scott catalog value of stamps issued in 1847-57 and most later classics by at least 50%. Because the ink used for writing in that period was not indelible, many of these cancels have been fraudulently removed and/or covered by fake stamped cancels. Often the removed cancels can still be faintly seen as very light brown lines, particularly on on-line blow-ups. Again, use exteme caution when purchasing any US classic (or Duck) stamp being offered as mint no gum (MNG).