Hi, Jim,
That is the trademark "ALFA" used by Armero Especialistas Reunidas (roughly, "United Specialists Armory") in Eibar, Spain around 1920.
I hope you don't have much in that gun because, in all honesty, the Spanish guns of the period were almost all pot metal junk, and the Alfa was not an exception. They were poorly made and the combination of S&W and Colt lockwork was common as being the cheapest and easiest to fit. The whole gun is made from cast iron and not even good quality cast iron. There are no parts available and the gun would not be worth fixing if there were.
In .38 Special, they are dangerous enough, but many do not have shoulders in the chambers and will take a .357 Magnum, which is almost guaranteed to blow the gun apart, as is .38 Special +P. All this is not from reading, by the way; I have seen several of those Spanish revolvers blown up, including one fired with a .38 Special blank.
If there are "gun turn in" programs in your area, you might take the anti-gun creeps for $50 to $200 for that gun. Otherwise, I recommend you either destroy it or grind off the firing pin and treat it as a wall hanger.
Jim
