Tower "Pinkerton" Detective Cuffs

Hello all,

Awhile back I was lucky enough to win a pair of the Tower Pinkertons on Ebay. Like many of us, on several occasions, I had to buy me a key from "our good friends Mark and Sheila." My question is, were these flavor of Towers supposed to have a double-lock? The key I purchased works flawlessly, but the lock is a bit hard to manipulate when unlocking the cuffs. I've used WD-40, but makes no different and wanted to make sure the key is supposed to only rotate one direction. Can one of you guys shed some light on this.

Thanks,
Kris

The Tower detective model does not double lock.
This is a neat looking cuff, and the set I have are also stiff when unlocking.