The photo is believed to show the survivors of the Rakuyo Maru in PT kit with their Physical Training instructor, R Austin A.P.T.C, whilst in rehabilitation. The signatures are from the back of the photo so are in reverse order to the photo.
Left to right in PT kit: with links to their page in the Roll of Honour-
Backrow:- Wilfred Barnett - H. Smethurst - R. Austin (A.P.T.C) - Frederick Ernest Wiles
Front Row:- A. Ogden - H. Jones - H.E. Wilson - C.M. Lowden
Frederick Wiles story is at:- http://www.far-eastern-heroes.org.uk/frederick_ernest_wiles/