Ad says Caprice but definitely Impala, which it also says on the body side emblem. Clueless sellers. http://newyork.craigslist.org/que/cto/5022437344.html
Considering it must be a decade since I saw a 70s box in person around here, this one is a rare survivor. That rust is normal repair around here, not a huge job at all. A bit of patch work, and it could be a decent driver for a good few years. At least the roof over the A pillars is intact.