I remember bangles being a big trend in the 80's, I had a few up my arms, most of them were silver, or enamelled with etched in design, most of my mates had a collection of them too. We used to pick them up at a store in town that sold ethnic clothes, fringed bags and joss sticks etc. Then it became the rage to wear rubber bangles..the goths wore black or purple ones, and the rest of us wore neon colours. But I don't know anything about slave bangles though!
I remember a girl I used to chat to on the bus, told me that her boyfriend would give her a bangle everytime they did the deed - Thankfully she could still bend her elbow and hadn't progressed to the other arm before they split up ..oh dear!