I purchased this from a car-boot today ive never seen one like it although it doesnt look unlike a custard cup but a lot bigger at over 4" tall and just over 1/2kg in weight from my research i think it might be classed as a deceptive glass or type?? it has an applied handle done like custard cups also. Lots of wear to the base i think its mould blown as there are no seams up the sides either i feel its quite early. Any ideas?