All that can presently (July 2019) be gleaned about Sydney Chapman from sheet music covers and by internet searching is that he has 5 works published between 1907 and 1913.
Of ragtime interest is Oh You Rag! (1910) published by Edw. M. Koninsky & Bros Music Co., Troy, New York, USA.
Surfers are welcome to contribute information about this composer.
This list is arranged in chronological order and contains 5 works by Sydney Chapman.
It does not claim to be complete and represents only the number of items located.