The original version of the HST Guide Star Catalog (GSC 1.0, Lasker et al. 1990, and following papers) contains systematic errors which typically begin from the plate center and increase with radius (Taff et al. 1990a). In a residual plot against CAMC stars this shows as high correlations between neighboring residuals. This is due to the inability of a global polynomial to map the metric of a Schmidt plate. A new reduction of the GSC measures (GSC 1.2) based on the subplate method (Taff 1989) is partially complete. We report on it for the northern data from the Palomar Quick V plates, with 20 minute exposures, nearly all taken in the 1982–1984 interval.