43 West 23rd Street was built as a warehouse in 1897 (Henry Hardenbergh) and in that Beaux Arts era, even warehouses had panache. There’s something to arrest the eye on each floor, from the big cat friezes on the ground floor to the pilasters (half columns) on the second, to the arch windows on the upper floors.
The building was later home to the Girl Scouts, Touro College, a showroom for carpeter Huffman Koos, and the entrance still announces it as the Castro Building, the company that was the first to conquer living space.
Hoffman & Koos was not a carpenter–they were a furniture store out of Hackensack NJ–or at least their largest store was there kind of kitty corner to Riverside Square. I think it was earlier Hoffman and Boyle? I still have a set of bedroom campaign furniture I bought there in 1974! Went thru a few incarnations before going out of business as far as I know in the 80’s.