The Aero Monorail was a futuristic monorail train that first hit the market in 1932. Manufactured in St. Louis by the eponymously named Aero Monorail Company, it was designed to suspend over Lionel standard gauge track and run faster than the standard gauge train.
The stands came in two varieties: a pair of free standing towers, and a series of towers that slipped under Standard gauge track and used the same 42-inch diameter. The motor looked like an Erector motor and ran on 6-8 volts, either DC or AC.
Aero advertised in magazines like Popular Science, Popular Mechanics, and Science and Mechanics in 1932-1934, billing it as the kind of train you’ll be riding on in 1980. The address, 2712 Big Bend Blvd., would be in the suburb of Maplewood, near the intersection of Big Bend and Manchester.
My research indicates the building later held Metalife, a chemical manufacturing company, and later, an ornamental iron manufacturer. The state tore down the building in 1966 or 1967 to add left-turn lanes to the two roads. A CVS pharmacy now occupies the corner nearest the building’s former site.
Even though these sets were made in St. Louis, the area isn’t exactly overrun by them. The sets came out at the height of the Depression, and that didn’t help. The introductory price of $7.95 works out to $147 in 2015 dollars, so it wasn’t a cheap toy. An already assembled, ready to operate system started at $12.50 and could run as high as $60. Aero painted the cars with enamel like the Lionel trains of the day, rather than using lithography like some other brands. It was also possible to buy the motor separately for $1.98.
Precious little is known about these sets or the company that made them. It received one mention in Louis H. Hertz’s 1956 classic Collecting Model Trains, which noted that the 1933-34 Chicago World’s Fair featured monorails. The Q&A column on obscure manufacturers in the Train Collectors Association’s Train Collectors Quarterly gets a question about them every couple of decades, all of which points to not many of these sets selling and the company not lasting long. The last ad I can find for the company was in early 1934.
I wouldn’t say they’re common at all, but that doesn’t automatically make them exceptionally valuable either. To make them valuable, there has to be demand for them too.