At my dad's house I have an old BSA Scorpion pistol minus sights, and the trigger doesn't work. When you cock it the sear doesn't catch the piston. Is this a common problem with the Scorpion and is there a simple fix? I remember having the gun apart many years ago to see if I could fix it, but it all looked very complicated so I put it back together again to let it gather more d/rust. If I could just get the thing working I'd then start the search for a set of open sights.