This bank building at 250 West 23rd Street, now an Emigrant Savings Bank, was built from 1946-48. According to building records, the architects of record were Frederick L. Ackerman and Charles G. Ramsey, but on the building itself is carved “Harold R. Sleeper, Architect” with the other two men listed as associates. Ackerman designed apartment buildings and some public housing in Manhattan. Sleeper and Ramsey are most well-known for publishing the book, Architectural Graphic Standards in 1932; a book which still remains in print and is seen as one of the definitive guides on the subject.
Emigrant has a number of mid-century buildings (featured here and here), some of which they had built themselves and some, like this one, which they acquired later. Seen here are two original details including a floral motif on the facade and a metal clock.