I just received a pair of unmarked swing through cuff with a screw type key way at the top of the cuff. The bows have round holes where two prongs are engaged to lock them. The key pulls the two prongs out to release the bow.
The seller says they are German WW ll and came out of Poland.
Doing some searching from previous posts I found some posts by Josef stating that if the swivels were ball shaped they were made in Poland. Most of the pictures have been removed but Josef's site showed several pair.
Here are some pictures of the cuffs. Any comments as to origin wound be appreciated. I assume they are 1930-1940's.