For those interested in replacing Floquil paints, there may be a new option worth exploring: Archive-X paints. I haven't tried them out.

Studio scale modelers scratchbuild replicas of models used to make movies (like X-Wing fighters and the Enterprise), at the same scale, using the same vintage kit parts—and the same vintage paints (SP Lettering Grey is the base color for Imperial Walkers). Like us, they are very interested in replicating Floquil enamels, and some of them got to mixing paints.

Archive-X is the result, and it appears they may be offering acrylics down the road. These guys don't care much about railroad colors (see: Milwarkee Orange), but they do care about getting the colors right! 

Here's the group's FaceBook page, with a pdf of available paints and an order form. And here's a look at the bottles. These are not cheap!