I will document the assembly of No Problem Joe's, an HO kit from Grandt Line Products. It was missing a set of doors and had extra windows. I am expecting them to send me the correct part.
I painted the wood panels with a light tan paint. I used a thin coat of this to act as a primer. Once this was dry, I added a coat of Rust to all the external walls. Using a paper towel, I immediately wiped it off pretty aggressively in the middle of each part and less so on the outer edges.
The roof was done using a similar technique. The main difference is that I used Brown this time. I was not nearly as rough while removing the brown. This adds to the contrast between the walls and roof.
I used GunMetal on the flashing. The window and door frames are White.
It's hard to see the detail on the above shot, however this weathering technique looks really effective. I'll use it again.