Humpty Dumpty Egg Cup

Child's porcelain egg cup. No manufacturing information. The back has A B C in blue. It is a petite 2 3/4 inches in height. I am not sure of the age, but I've had it (actually, had 2 and still looking for the other) for over 15 years and it was not new when purchased. No chips, cracks, breaks, roughness, loss of finish or repairs. There is one pin point dark spot toward the rim - not sure of what it is, because there is no roughness and seems to be glazed over. I will be happy to provide additional photos. I need your zip code to calculate the postage.