When the Warhammer 40.000 6th edition came out, a new space marine chapter was illustrated among the most know. The Guardians of Celeres was used as example but nothing more was written about them. So when I bought the "new" space marine squad (I bought it with a friend because the EXPENSIVE price of this sprues, five for him and five for me) I thought on painting them with this color scheme.
They were mounted simulating that all of them wears an old MK VI armor but along the battles many pieces have been replaced. So I used the two Corvus armor helmet for troops and the rest were mounted with human heads but adding them a MK VII helmet on the back.
In addition to this squad, a Captain was mounted using a MK III Forge World components and remaining pieces from the sprue. The original illustration for the Guardians of Celeres is an space marine equipped with a flamer and wearing a MK III armor and a MK VII helmet so this Captain keeps reminiscence with the illustration.
The sergeant of the squad wears a mixture of armors. The legs are from a MK IV, the chest its from a MK VI but with a winged skull plaque (that's why it seems to be a MK VII chest), and the helmet on his back it's a MK VII.
The troops pieces has been combined among them to look more "Corvus". One of the guys without helmet wears the only shoulder pad with pins available in the sprue (GW, you can take all the purity seals, combi weapons and shits like that and put it into your nurglesque ass) and the other wears the more similar MK VI chest plate.