Darby Handcuffs from RCS, Hiatt, and Thompson

First off, here is a prolific example of the false backstrap Darby by Reuben, Craddock and Sons. Prior to this design, the backstrap was formed from the tail end of the shackle being bent back over into the outer surface of the cuff. 

Note the two dots at the lock end of the cuff; this indicates size 2, which is a snug fit about 7.5" approximately. This size is the most common, although there are sets in size 1 and 3 as well. 

This set is listed at $175 starting bid and only 19 hours remaining. 

These have a great authentic patina and wear. These are stout handcuffs with broad bows. 

Above, RCS typically has some numerical markings like this on one end cap. The seller states these are marked 1943 for production and 63 for the matching keys. 

Below, these have two matching keys. 

Here is a very good condition Darby handcuff from RCS as well. This is a later production marked from 1956 with the more "modern" Darby design as compared to the previous example. 

This is listed for $295 buy it now or best offer. 

Above, these are additionally marked for HM Dartmoor, the infamous English prison built in the very early 1800s for prisoners of war and later converted for domestic incarceration. Recently, it was shut down due to high levels of Radon gas. 

Below, the Broad Arrow marking on the hinge below the keyway. 

Finally, a more common Hiatt model 104 Darby handcuff with nickel plating and one key. 

Here is a very rare Darby handcuff from Thompson, one of the earliest makers of the Darby design. 

These are listed at $500 or best offer. 

These appear to be a smaller Darby with stout construction. the key is reminiscent of the Providence Tool Company key shape, while the hinge angle is also similar. 

These have a beautiful dark patina.