tower cuffs questions

I have a pair of tower cuffs.
I have some basic questions
1) there is a slot in the middle of the curved bar is this standard or are they missing the stop?
2)they have a stamp in the very center of the hinge "hinz" what does this mean?
3) there is another stamp larger on the lock itself the #495 what does this mean?
4)they have a key that opens one side where can I find a key that works bothe sides?
Thanks for any info
Cowboy

Question #1: You're missing the Tower "Stops".

Question #2: From the Don Hinz collection/The handcuffs were obtained from him.

Question #3: "495"...sorry,no idea (a factory or collector's stamping?)

Question #4: Write to magicduo@cannonsgreatescapes.com


Joseph Fox