It may not be officially broken, it may have been "fixed" that way on purpose. Back in the late 1950s and 1960s there was a revolver competition that required the pistol fire only in double action. I don't remember the "official" name of the competition, but it was popular for about 15 years and then interest faded until it disappeared completely. Most guys would have a standard S&W "fixed" to fire in DAO, but some didn't want to go that far so they'd have a Spanish or some other S&W clone "fixed" to fire DAO. Over the years, so many folks were bringing these "broken" pistols into the shop for repair, that we had a box of parts and a bench dedicated to changing them back to original configuration. I don't remember the exact parts replacement procedure, but as others have mention, it wasn't all that difficult (even I could do it!) and it wasn't all that expensive. How about some pictures after you get it fixed? Best of luck