Hello:
 
Try contacting your local state/federal prison.  The Folsom State Prison here
in California has a museum that includes displays of handcuffs, billy clubs
and other restraining devices that look more like torture tools.  The prison
started in the 1870s and some pieces in the museum predate that time frame.
 They have some history of the equipment in some displays.
 
If you strike out locally you could call Folsom Prison.  The main prison
telephone number is 916/985-2561.  They have connected me to the museum in
the past.
 
Good luck,
 
Mary Maniery