I've seen claims somewhere (maybe at "Watts Up with That") that no unmodified climate station data exists, that it's all been modified or corrected to adjust for something.
Well, it does exist, you just have to go back to the original sources, e.g. the meteorological organizations of the various countries, militaries, etc.
As far as I know, the position of the CRU is that they have no original unmodified raw data anymore. Don't know about NASA and NOAA.
This article claims that 3 out of the 4 datasets available, the ones from the CRU, NASA’s Goddard Institute for Space Studies (GISS) and National Climate Data Center Global Historical Climate Network (NCDC GHCN), are not independent and that the latter two were felt by NASA to be inferior to the CRU's. The article doesn't have anything on the raw data, however.
As far as I know, the position of the CRU is that they have no original unmodified raw data anymore. Don't know about NASA and NOAA.