Short pants buttoned to shirt
Disclaimer #1 (Renton's Hair) - While there is much exigent documentation to show very short hair on boys during the Victorian era, most wore their hair longer (often curly) and always parted on the side. In fact, the side part on very young boys still in skirts was often the only thing that distinguished them from their female counterparts of the same age.
Disclaimer #2 (Renton's Boots) - The zip laces on Renton's boots are not accurate for this period. HOWEVER, when you are outfitting (on a budget) quickly growing children with footwear that they will not wear anywhere or anytime else, you get what you can. :)