This is a very nice and really quite small watercolour box by the great makers Winsor Newton of London. 
 
I think it was made sometime around the 1890s judging from its label but could be as late as the 1930s but I doubt it. It’s label lists it as a collage box and in later times they became a bit flimsy. Not this earlier one it’s built like a tank!
 
It is in good condition generally though of course it does have some scars from its long life. A bit like us all perhaps!
 
The outer and inner paint is quite good as can be seen. There is a bit of staining internally but nothing serious in my opinion. 
It does have a full set of ceramic pans by Winsor Newton and these could be original to the box. When these paints are used it is a simple matter to wash out the pans and re fill them with tubes paints. 
 
All in all this is an affordable pocket sized watercolour box by a famous make that is as useful today as it always was.