Tamiya Deck Tan looks nothing like Gull Gray16440/36440. Whoever se t that up a cros reference must have made a mistake. Sky Gray is much closer, but still too dark.
I am building a FJ4B Fury and I have seen photos (both actual aircraft and models) where the color ranges from a light gray/blue gray to a very brown gray.
The MM gull gray looked too blue IMO. I have done a lit of research but it is hard for me as I am 1 - not good at colors and paint matching 2 - have no idea what gull gray should look like in the first place.
Well from what I do remember of seeing Navy and Marine Corps birds at airshows from that era was that GullGray did have those tonal variations, especially depending upon the light. There is just the hint of a tan in there I always thought. I prefer Humbrol’s Satin or Gunze’s Aqueous Semi Gloss shade of Gull Gray myself. But a dab of Deck Tan and a bit of White added to the Tamiya Sky Gray will give a reasonable approximation.
Gull Gray comes in two shades, Light (x6440) and Dark (x6231). Light Gull Gray is a light color with a bit of a “concrete” shade to it; Dark Gull Gray is a blue-gray almost akin to USAAF Neutral Gray. The IPMS Stockholm color cross reference says XF-20 Medium Grey is a close match to x6440, and XF-54 is a close match to x6231.
In my opinion, XF-20 is still too dark and should be lightened up quite a bit for x6440. XF-19 Sky Grey is too blue and still too dark for a Light Gull Gray. XF-54 Dark Sea Grey is also too dark and not blue enough.
If you can get Model Master, their Light Gull Gray (FS 36440) and Dark Gull Gray (FS 36231) are both pretty accurate, whether Acryl or Enamel.