Complex sentence: Schubert served as manager until retirement, except for 1937 when he worked in an executive post with the New Yorker Hotel, NY, NY, returning to his Adolphus Hotel duties at the close of 1937.
Split into simpler sentences: Schubert served as manager until retirement, except for a brief stint in 1937 when he worked in an executive post with the New Yorker Hotel in New York City. He returned to his Adolphus Hotel duties at the close of 1937.