Retooled. A real shame. If left alone, the coin had enough detail and luster to grade AU-50 on its own merit. Unfortunately, some greedy person was probably trying to get it up to an uncirculated grade by retooling the coin. Formerly in a NGC AU-58 holder. It was a tough decision whether to lose perceived equity in the coin by crossing it to a PCGS Genuine holder. Due to the low population of the coin overall, I decided to cross it for my PCGS set; as it is a tough coin to come across in any grade.
The 1875-S over CC Trade Dollar is one of a group of interesting and unexpected varieties created when mint engravers used dies intended for one of the branch mints, then overpunched the mintmark with that from another. Thus, we see coins such as the 1875-S/CC Trade Dollar, the 1900-O/CC Morgan Dollar. and later issues such as the 1955-D/S Nickel, all of which are important coins to collectors.
Currently, the 1875-S/CC is the only major Trade Dollar variety recognized by PCGS. As such, it is the rarest of all the Trade Dollars in Mint State, even edging out all of the celebrated CC issues. Of the 79 examples shown on the PCGS Population Report (as of January 2014), all of the survivors are distributed over a range of grades from MS61 to MS64, plus a lone PCGS MS65. The 1875-S/CC Trade Dollar is one of only four dates in the series that is not represented by coins above MS65 (the other three are the 1873-CC, 1874-S, and the 1876-CC).