Here's one more for you but I don't want to hijack your thread. I've never heard of a Black Cow Float though. During the 30's & 40's this is what we know now as a Root Beer Float with some chocolate syrup added in.
I was always told that a black cow was either chocolate ice cream with an orange soda on it or a black angus cow.
This is what I found first off in a search. Sounds rather yummy. "The root beer float, also known as a black cow float in the thirties and forties, was root beer mixed with a couple of shots of chocolate syrup and topped with vanilla ice cream. We’ve attempted to re-create the old black cow experience with this flavor. It’s a root beer–flavored ice cream with swirls of milk chocolate."
