The key date period represents a major challenge for locating quality high grade examples. The dark toning and weak lustre found on many of these dates is due to the recycled bronze source. Between 1864 and 1871 stockpiles of old Large & Half cents were melted and recoined into the Indian Head & Two cent piece, resulting in heavy woodgrain. When these ran out, the Mint resorted to melting the 1864-1871 Indian Head & Two cent pieces to produce 1872-77 Indian cents. This 'third generation' bronze became the least eye appealing alloy of the series and makes true red survivors extremely rare. It wasn't until 1878 that the Treasury Department contracted outside sources for bronze planchets.
Any collector who starts out today to assemble a full set of attractive Indian cents should expect a long time frame in this period alone. RB and 64RD examples can be more realistic alternatives, and in many cases are more appealing coins.