It could have been a special occasion outfit for a church, birthday, funeral, wedding, graduation at a private school, etc. The cutaway jacket isn't something a young lad would have worn for everyday wear, it would been too pretentious like wearing a ballgown to a barbeque.
Judging from the measurements you gave me before for Jake, it would fit about a 5-6 year old depending on weight and height (it's just a snug too small for him in the waist and he's 7 next month).
Definitely not a servants outfit due to the poshness of it and by the date this was made, young children would not have been in service.
The label doesn't seem old enough to be 1900 as well it looks more modern Art Deco in styling than antique . I 99.9% sure it's a special occasion outfit from the 1920's- first half of the 30's. Those bakelite buttons on the tops and trousers are typical of what you see on men's things of the era and the waistline of the trousers seems about right for that era too.
The wideness of the lapels is also right for the era too.
It's a nice one as boy's stuff from any era is hard to find and if it had just been a touch bigger then I would have snapped that up for Jakey! :D
Lei