For any who are interested in better understanding conditions at Bisley and the other Shaftesbury homes, there was a film made in 1937 called "Citizens In The Making". This film was for fundraising purposes, but does show images of each of the schools and the ship Arethusa. (This includes Royston, Bisley, Fordham, and Shaftesbury Avenue.)
My father-in-law (Richard Williams, b. 1926-d. 2000) was in the Shaftesbury system following the death of his mother (in 1932) and grandmother (in 1934). His brothers Tom (b. 1924) and John (b. 1928) were also in the system.
Following his time with Shaftesbury, he joined the army and served in Egypt and Palestine.
I was able to obtain a copy of the film from the British Film Institute.