I have no direct answer to your question, I have never heard or seen real Stone Pianos in Chicago. Where does your source come from? I know where the first and only Stone Piano in the world is that I know of and it is not in Chicago as far as I know.
Howard pianos were built by Baldwin Piano and Organ Company 193388was built in1927
The Blue Book of Pianos shows that Bradbury manufactured pianos with serial number 98000 to 125000 between 1930 - 1935. Given that information, your Baby Grand with serial 118453 was mot likely built sometime in 1932 - 1934.
Doorway thresholds can be built from materials such as wood, stone and metal. You can get more information about doorway thresholds at the Wikipedia website.
They were built with stone and in square shapes lolololololl
The Colosseum is built with concrete, faced stone, stone and marble.
Stone
They were built with stone and in square shapes lolololololl
The Romans built stone-paved roads.
The first working nuclear reactor was built at the University of Chicago. This was the Chicago Pile-1 (CP-1), and you can find a link below that will bathe you in information.
stone castles were built with stone
The Land Tejas Company built the Stone Gate development
L. Avisus Piano Co. specialized in grand and upright pianos. They shared an eight story building built in 1896 with Russell Piano Co. at 249-251 S. Jefferson St. in Chicago IL.