Ron Guth: The 1880-CC 8/Low 7 is one of the more common varieties of the 1880-CC $1. The most obvious difference between the Low and the High 7's can be seen by the position of the base of the 7 relative to the 8. The Low 7 is much farther from the 8 than the High 7. Both of these varieties are Reverses of 1879, with a nicely rounded breast on the reverse. Additional overdates can be seen on the flat-breasted Reverse of 1878.
High grade examples of the 1880-CC 8/Low 7 can be obtained easily. The PCGS CoinFacts Condition Census (a listing of the Top Ten examples of the dates) consists of MS-66 to MS-66+ examples, the finest being three at the MS-66+ level).