Nice looking yo-yos Gary.......
When I was a kid, there was the Duncan Yo-Yo craze. If someone else's memory is more distinct about it, let me know.....but I think this was the early 1960's when this craze was hot. I remember everyone at school had a yo-yo, and we did all kinds of tricks with them........well, other kids did all kinds of tricks, as my tricks were pretty basic!
Anyway, I was browsing the Packard catalogue the other day and saw some "ball bearing" yo-yo's. At first thought, it occurred to me that ball bearings defeated the "catch" of the string. As I remember, the string looped around the axle which was polished. When you yanked on the string, the loop hung up, and caused the yo-yo to wind the string, which in turn caused the yo-yo to climb up the string. It just didn't seem like an axle that revolved on ball bearings would have the same sort of action to it......
ko