Now. I was looking at some of the higher prized versions of my gun and a feature that I thought was utterly amazing was the mainspring housing that is flush with the frame. My question is, at this point ... can I order a mainspring housing that is flush with the frame, or is this something a 'smith needs to grind down, thus involving refinishing and labor costs? My second question is a bit less related. If I order a safety online (a thumb safety, that is) is that potentially drop in or does that have to be fitted? Thanks Already!