For reference purposes, I'm adding some pics of this Amber Stolzle : Hermanova Hut : Shell Shaped Bowls/Dishes set. Bought to sell on, but have grown rather attached to them, particularly the stubby little feet which all balance perfectly!
Pattern Numbers could be 19504 or 19508?
Large bowl measures approx 27cm across the widest point x 8cm high, displays 4 dots each side.
Small bowls are all stamped underneath "CZECHOSLOVAKIA" and measure approx 15cm across the widest point x 5cm high, display 3 dots each side. (Can just about see the stamp in pic 3, it's difficult to get a good photo of it).
19504 sizes in catalogue : 15, 24, 29cm.
19508 sizes in catalogue : 26cm.