Try FS 16081 Engine Grey. I believe model Master carries this in their range. I built the Airfix 1/72 kit some years back. Not a bad kit for its age. Except for a few C models flown during the Vietnam War, US Navy types were in high vis markings with full color US insignia and lettering in white. Superscale made a 1/72 set of decals, but I am not sure of their availability. New Zealand operated SH-2F's in what appears to be Light Ghost Grey livery with medium grey markings. Do an on-line search and I'm certain you will come up with a lot of photos. If you search the Finescale forum archives you will find photos of my Seasprite. Good luck and shoot some pics of the kit when you're finished.