NY Egg Creams--definitely remember them. I still make them once in a while. I think it's made with half-and-half though, not milk? Tastes like there are eggs because it's so rich. I'm surprised they aren't more popular.
I also love an Italian soda (hazelnut or what have you).
If memory serves me right, the Coke was made by combining the syrup with carbonated water by the "soda jerk" rather than starting with already made Coke. If someone wanted a Cherry Coke they would add a squirt of cherry syrup before putting in the carbonated water.
That makes a lot more sense than adding syrup to premade soda. Sounds good actually.