I have altered it by sewing the button closures on the sleeves together, but it is hand sewn so if you want to seam rip it you could (see photos)  You could button it like normal after that. The sleeves were very tight which is why I altered them. 
Some of the buttons may have been sewn back on and one of the black bits on the buttons had to be glued back on. 
This description makes it sound so janky but it’s a really decent blouse after a little ironing! 
Bust is 18 inches flat
Waist is 15 inches flat
Sleeves are 6 inches flat (with alteration) without alteration they are about an inch smaller.