The Great Depression was not easy on any automaker, but an independent luxury brand like Packard had to play its cards right in order to survive. The 1935 One Twenty earned Packard a stay of execution, allowing the brand to bring some flavor to the medium-priced class. Two years later, the Packard Six took the brand even more down-market.  The jury is still out whether the junior Packards hurt the brand, but there's no doubt that it helped…