Mattatuck Handcuffs with box

 Here is a near mint set of Mattatuck handcuffs. The original box and instructions are in fair condition with some taped edges. One original key. 

These sold for $281 after 25 bids. 

Below, close up detail of the unique key design. The lock mechanism on these is known to be somewhat confusing. The double lock and the unlock function are both done via key; it depends on which side the key flag is inserted into. There is also some sort of anti picking device that the downward portion of the key engages with. I believe it may be a sort of spring loaded disc that blocks the keyway.