Label Era Identification

The one thing I struggle with most when it comes to selling vintage is dating pieces & I'd really like to become more versed in identifying eras instead of making blind guesses. Does anyone have an idea when this top was made? My best guess is 40's or 50's. The Label reads "A Royal Blouse" the e in blouse is hidden under the seam. Googling has only made matters worse because of how common/generic the name is. Any help is appreciated also very happy to have found this community with so many helpful resources!

 

With those bust darts and waist tucks, I'd say mid to 1950s?

 

Thanks for the input and also for mentioning the darting/tucks that's helpful info I can include when I list it and also use for identifying clothing later on!