Well, because it is clearly a .25 it isn't a Ruby, but I have no doubt it was made by one of the many contractors for the Ruby. In the pre-WWII era tens of thousands of those Spanish clone type .25s (with components built in peoples homes one part at a time) flooded the world (also .32s and .380s). That's a crossbolt safety, and it is very possible a crossbolt safety from another pistol of that era can be made to fit. I would pick up a used 1908 safety and make it fit, if it was mine. Then I would dump it on Gunbroker if I didn't know who the people in the grip photos were. Set your reserve price at $50 and someone will buy it.