Top one is a '49 or '50 Frazer (only ones that had the hood medallion mounted on the top grill bar as shown in the picture). Bottom one is a '47 Frazer (only '47s had separate letters for scripts). The only way to tell on the '49/'50 is looking at the body tags as Mike points out. It won't make much difference as the 1949 and 1950 cars are exactly the same.
