Actually, I believe that Testors has a spray called "Battleship Grey". I don't know if that is the one for you, or Gloss Gull Grey. With so little color reference material available, you may have to use that 40's era car photo above as a color chip.
I also noticed in my original Google search that some cars appeared in either dark blue, or black. Still others were olive drab... maybe they were not Navy specific photos? Not every photo on the net is accurate (I think I just made an understatement!)