According to Wikipedia, 52 episodes of Dragnet from the 50s have been released as PD episodes in DVD sets. And yet the largest amount I have seen in a set is roughly 20-25.
It boggles the mind that the masters to the 50s Dragnet are in some vault at Universal. The entire color 67-70 series is on DVD, so why not the entire 1950s series? It would make sense for NBC/Universal to strike new prints and syndicate them to Me-TV and other channels while creating season...