The New Boy
There appear to have been two plays by this name, both from the mid 1890s:
The New Boy: a comic farce by Arthur Law
Arthur Law () based his play on F. Anstey’s popular book Vice Versa, and the play opened The New Boy at Terry's and opened at the Vaudeville Theatre, London, on February 28, 1894, with Weedon Grossmith in the title role, running till April 1895.
The first American performance of was in Bethlehem, Pennsylvania, on September 14, 1894.
The posters for Law's play are speculated to have been the source of the famous Mad Magazine cover image of "Alfred E. Neumann". (See the entry on this in Yesterday's Papers, a blog by cartoonist, illustrator, storyteller, John Adcock at http://john-adcock.blogspot.com/2013/03/the-face-of-new-boy.html.)
The New Boy: a comedy by R.R. Lumley
The source for this attribution is F.C.L. Bosman (1980, p. 403, citing D.C. Boonzaier), who ascribes the play performed in South Africa by the Ernest Searelle Comedy Company to "R.R. Lumley". Given the fact that the named of the company is almost certainly wrong (it is probably the Luscombe Searelle Comedy Company), it is highly probable that this was also Law's text.