@Red Corsair : Thank you very much !
-The pink is applied on a white base, then a first layer of Prince august G14 "pourpre violacé" of their games range (I guess it is similar to the Vallejo Warlord purple G14), followed by some white highlight (or drybrysh depending on the detail), and then a second thinner layer of "pourpre violacé" (Pretty surprised I was unable to find the english name for that one)
-The gold starts on a brown basecoat, followed by a layer (or two) of vallejo brass, and a final layer of agrax earthshade
@Luciferian : Cheers, much appreciated ! Pre paint shots are spoilered below.
-I started by shaving any loyalist icons on the primaris legs and torso, filing the parts that would be left bland, and covered the roughest parts with mutated speakers (e.g. the champion's right knee) or faces.
-Then I had to connect the arms and greenstuff some of the joints so that they would fit. The blastmaster gave me some headaches on that matter, so I had to resort to an upper handle, out of an heavy bolter I think.
-Also custom built two backpacks out of primaris ones, so that all members of the squad have a special one.
-The plastic sonic blasters were cut from their original arms, moving him to the left arm for the champ, and slightly rotating the other one to fit his holder's pose. (Also mercilessely widened the left hand (an original bolter holding one) of that second marine so that it would accomodate the gun)
-Finally, headswaps, one from the betrayal at calth box for the blastmaster guy, a Wargame Exclusive not tzeentch helmet for the champ, and ROTTEN_FACTORY helms for the other three.
Not all the greenstuff is handsculpted, I also lazily molded and pasted some elements, such as daemonette heads, then reworks them before the GS
It think that covers the build, but let me know if I overlooked some details.