Are these for very hungry people? Or for very close relatives? The proved fact is that they are called 'twins'.
Unique details: 1) Aberdovey (Wales) souvenir egg cup, produced by Bukfast, a Devon company which made the same model also for other places [eggcup1823]; 2) Carlton Ware egg cup, marked "Carlton Ware, Gourmet, England", [eggcup1672]; 3) Irish egg cup [eggcup1591]; 4) bought in Brussels, 1988 [eggcup0821].