Advice on Floquil paints?

[Steamtrains]

I don't know when the new formula came out, but on my roundhouse project I used Roof Brown with lacquer thinner for the initial staining, and the pigments settled to the bottom of the jar. I also had a can of mineral spirits laying around and had wondered what I used it for. Then I recalled that I used it for the same purpose when working on the little one-stall engine house, and did not have this problem. So I would recommend using the mineral spirits, especially since you'll be spraying.