That's the same method I'm using. Just going back and giving it little more weathering. My GML wants me to get rid of a lot of white so I'm also trying to dull the white down with the cloth I used to rub off weathering and a little water. Then I'll go back and add the 3 color mix for the oil look just like he did in the tutorial. Fortunately, the "look sir, droids!" has quite a few SWAT level approvals to look at. From what I can tell, the majority of weathering is kinda open to interpretation except for distinct markings. I've seen some a lot dirtier than others. You're definitely on the right track. Hopefully one day we can troop together!