It is well known that Rohn and others originally made blank firing revolvers. In the Germany of 1920-1940, crime was rampant, but the average citizen could not obtain a gun to fire live cartridges, so blank firing guns, both revolver and auto types came on the market.
After the war, most people who wanted a gun (for good or ill) could get one relatively easily, so there was not so much demand for blank firing guns.
But one thing Germany needed badly was hard currency, spelled "dollars". So the makers of blank firing handguns revived their blank-gun lines, changed the guns just enough to pass proof tests and made them for live ammunition. Most were sold in the U.S. often by companies that also sold cheap cigarette lighters, fake "SS" knives, and similar junk.
Those guns sold retail for as little as $9.98, and probably cost about $2 to make, so they were not exactly high quality. Still, some times they held up surprisingly well; in U.S. government tests, some samples fired 5000 rounds without failure!
The "$9.98 Saturday Night Special" became so ingrained in the anti-gun rhetoric that only a few months ago I saw an editorial demanding a ban on "ten dollar imported pistols".
Note that though originally intended as defense weapons, they were generally imported as "starter pistols", so as to appear more innocent.
Jim