Finally, it's starting to look like a Blood Pact vehicle! After several poor airbrush experiences I went to the art store and picked up some Montana brand spray paint. They have a ton of colors, are good quality and come with the ability to switch out the spray nozzle. This allows for wider or smaller, higher or lower pressure. After a couple pictures I'll show you the technique I used.

AT83 Brigand: Counts as Leman Russ, here with Battle Cannon, Lascannon and coaxial Storm Bolter.

The brass-etch chaos star
blends nicely on the flank I think.
Ok, I don't have a step by step guide but here's the process I used:
1: Prime entire model white with airbrush.
2: Get frustrated with airbrush and buy rattle-cans.
3: Spray all parts of model black on the underside to pre-shade.
4: Spray entire model dark red.
5: Spray all parts of model bright red (ketchup) from the top to pre-highlight.
Here's a look at the side of the model. You can see it is quite bright towards the top and fades to a dingy red towards the bottom.
See the difference here; the top of the turret is bright red, the sides are dark and the top hull is bright red.
I played a couple games and didn't like using my officer model as a Kommissar so I got to building and converting. It was an unholy conjoining of game necessity and conversion inspiration. I'll leave you with a sneak preview of what's to come:

(Melta gun is from the Chaos Raptors. Being metal it's quite short and works well in the smallerm human sized hands of the Blood Pact.)