I have a vintage, all original ka-knockers toy from the late 1960's-early 1970's to trade. Those of us old enough to remember and had these will remember these acrylic balls on string and the fun and joy, plus the bruised knuckles, wrists and hands that came along with them. They have been banned from manufacture in the US since 1985 and eBay has banned their sale. These are all original down to string and the plastic finger ring. The balls are that late 60's-early 70's pine green with gold glitter and DO have a few chips at the bottom. Email me for more pix.. These are not intended to be used, just enjoyed as a memento of your childhood as the original string is brittle.
I will trade these for $35 in insulators. I pay shipping to you and vice versa.