I think that top was made in a sand molded pour. That would make the roughness and not hurt the handling. It would have probably been poured with the spike down in the sand mold forming.I would really like to have it in my old jar collection. But it is a neat one to have on your shelf for conversation. I must have a good two hundred discussion pieces here in my bottle den.They range from big demi's all the way down to my little Coca-Cola. And include a lot of unique mold making and glass forming subjects to discuss with bottle people visitors. RED Matthews