Don't change the design, it’s a Lefever keep it exactly as it was designed. There is no such thing as a mechanical safety, all mechanical safeties fail. The ONLY safety that exists is to keep at all times the barrels pointed in a safe direction. But what does that mean, it means don't run and fall in a gopher hole cause your all excited about seeing a bird, spilling your gun on the ground like a fool. It means while your hunting you move slow, and I mean as slow as molasses in winter time, know where at all times to place your feet and approach all and I mean all situations, which takes experience, where it could possibly be dangerous and then move even slower.
All the best
