[Zilla]

Does anyone know the politics of why some of the movies have not been rereleased while others are?

I know Godzilla 1985, which I really want, may be a problem cause of the US ties, but I'm surprised the original 74 Godzilla vs MechaGodzilla is not on DVD while Terror of Mechagodzilla is. I never liked Son of Godzilla(not on DVD), but at lease that one is an original movie compared to Godzilla's Revenge, with retread footage, which was released on DVD.