I picked up what I assumed to be a common set of cuffs several years ago at a pawn shop. I noticed they were Smith & Wesson. I had also assumed any hand-cuff key would work, but it would not. I wrote S&W and provided the serial number and they sent me a set of keys and told me these were used to transport prisoners from pen-to-pen and only this set of keys would work. I believe they are nickel-plated and not stainless, but I could be wrong.

Any collector value here?