Set of 8 Vintage Blue & White Chinese Porcelain Koi Fish 8" Bowls READ

Items are pre-owned, vintage. There are signs of wear from age and use, such as light scratching to the surface. One bowl has a chip in it- I have circled this in one of the photos. One bowl has a black spot on the base that I am unsure if it is removable. I did not want to scratch at it too hard for fear I would damage the bowl.