Great video Arioch! I think there are a few things to add to information on the Strauss restraints. The handcuffs, you show, are considered a model 2. The first model is shaped differently and did not have a matching leg iron. Also, the reason these are that dull gray color is because of them being made out of Cadmium. I should also be noted that Cadmium has a possible cancer warning associated with it. Nothing to worry about with what is in the restraints you have, but ingested and soaked in through your skin in higher doses, can lead to kidney and bladder cancers. If too much Cadmium is inhaled into the human body, it may also lead to a form of lung cancer. So.....wash your hands after handling a set of Strauss cuffs! LOL!
I also wanted to point out that the design for the chain mount on the Strauss and the Harvard, can also be seen being used in the design of an English handcuff made by Civil Defense. The mount on this cuff is quite a bit smaller, but of similar shape. They made their handcuffs, from their version of a rigid cuff. They cut away the bar that joins the two cuffs on a rigid and leave this triangle shaped piece to attach the chain and swivels too.
-Richard Knip-
This is the Strauss First Model Handcuff, for reference. Picture is from Yossie's Collection.
And here is the Civil Defense Handcuff, to show the similar shape of the chain mountain plate, but much smaller. For reference.