Linked thread has the history of the Floquil brand.

"...Our company was founded in the early 1930s by Harold Rosenlund, who lived in New York City with his wife, a commercial artist and advertising illustrator. At the time, most newspaper advertising, particularly fashion ads, were illustrated with pen and ink drawings created by specialists like Rosenlund's wife. The artists worked under press deadlines and were always on the lookout for a better ink that would dry rapidly. Rosenlund invented an entirely new quick-drying "ink", along with a refillable pen that had a tip made of felt. His system worked well and became very popular with commercial artists and fashion illustrators. Few people realized that Rosenlund's new quick-drying ink, was actually a specially formulated enamel paint..."

--------------

Floquil paints were reformulated after the line was bought by RPM. Prior to this, the paints were well-regarded by hobbyists for how well it flowed and covered on plastic, metal or wood. Matching model railroad rolling stock kit colors was fairly easy. I miss the color but not the solvent smell.

I happen to have been digging up info the past month or two regarding Floquil, looking for suitable replacements for some colors. Today at this out of the way hobby shop I was able to find a bottle of the modern Floquil (acrylic), along with some Model Master acrylics and some Tru Color paint. Tru Color has a range of railroad paints, and may be a substitute for Floquil. After years of eschewing acrylics, I've recently tried some of Tamiya's and found it to be fairly good to work with (brush on).