The Wests First Grade Heritage List identifies player #183 as S.D. Matthews and player #189 as W. Mathews.
The Rugby League Project lists these players as S. Matthews and W. Matthews, both playing for Wests in 1917.
To further complicate the identity of these players, Wests team photos from the period show these players as S.W. Matthews (1917), A. Matthews (1917), D. Matthews (Reserve Grade 1919) and W. Matthews (1919).
The player was eventually identified as William Denham Matthews.