Update: See the house above in the winter of 2022.
Chances are, unless the house was built before the city annexed the neighborhood, if you see a wood frame house, it is very old, as in Civil War or older. Old North is a very old neighborhood, and was even a separate town, and I suspect the age of these workman cottages are from around that time.
Update: The house above was gutted by fire set by an arsonist on April 13, 2020.
I hope people see the value of them, as they are a rare breed that point to another time in St. Louis. Many are still occupied, but more are endangered due to their construction–not as robust as brick or stone.