sergestorm said:Keep in mind that the grips, triggerguard, and backstrap are "hand-fitted" to the frame. That means the unfinished pieces are assembled to the frame then ground down and polished. You may get lucky and the new parts fit nicely but the odds are against it. If you want it to look and fit like factory new, start with unfinished parts (all three, grip, backstrap, and triggerguard)
Cover the frame with masking tape and carefully file and sand the parts until they match up on the edges.