Brass Fish Lock

It was a gift given to me from my mother. She had found it at a thift shop and bought for $2.00 and it was a good buy. Its so shiny and unique. I recently did some reasearch and found out it was a brass fish hook with comes with a pin, lock and key. I do not have the key, just the pin and lock. I was hoping to find out more about the orgins and value of this antique.