The Italeri instruction sheets quotes the FS numbers as; flat medium green, FS 34082, flat light brown, FS 30219 and flat gunship gray, FS 36118. Are these the correct camouflage colours. Always though it was black, green, brown. Correct FS numbers would be appreciated.

You could also just use Tamiya NATO green, brown and black. I only use these for NATO camo schemes, and have always been happy with the results. You can see my M998 Humvee I did using these colours. Here is a link to the post:

https://armorama.kitmaker.net/forums/216316&page=1

For Italian vehicles at least, the red brown of Tamiya is wrong. The color should resemble that of milk chocolade, much less reddish.

He is building an M923, which is a US vehicle.

Just take it from me,some of the old Italeri kits would list using Model Master Sand as the overall camo for most German panzers.With your M-923 I would strongly recommend going with the standard NATO green,brown and black.

There's nothing wrong with their suggestion of gunship gray. It just depends how faded you want the black to look. CARC does fade, and black seems to be the first color to do so.