Unknown "Polish" Figure-8 Handcuffs

These handcuffs were purchased in Poland, they are said to come from Russia.

Made of brass, they are rather "delicate" in construction but solid and functional. Meant for small to medium wrists. Typically, used, one would assume, with hands facing opposite directions, in front. They snap locked. When the key is turned, the bolt disengages and the cuffs open. The "sharp" looking points on the inside are not very sharp, rather like those found on thumbcuffs.

When initially purchased, the cover plate for the lock mechanism was missing - a best-guess replacement is what you see in the photos. These may well be a "prototype" since the pin holding the two bows together can be unscrewed from the back side of the cuffs with little difficulty - the final product, one would assume, would have a more permanent lock mechanism.