Sadly, the admissions registers for Saltley Reformatory for the period 1902-1916 are missing from the archives. Newspaper reports offer the most likely alternative source of information. However, those that are accessible online are by no means comprehensive either in geographical coverage or of available dates. I've had a search through the British National Archive but with no luck. Sheffield and Leeds papers are available there, but not, as yet, any Rotherham ones, and coverage after 1900 falls off rapidly anyway. Sorry not to be able to help.