ID Model 94 Cuffs for me.

I have a pair of Model 94 Smith & Wesson handcuffs, serial number 755285, no key. I see that there are alot of special keys availabe but I do not know which one to buy. On the swing part of the cuff is a letter A stamped in the metal but I do not see a letter A key for sale. Any advice, information, etc.

A 94 with a A stamped into the bow works with a N key.