I have a 4516 with a bobbed hammer and would like to change it out for a spurred variety. Numrich lists a bobbed and spurred hammer for the 4566. I'm hoping one of you S&W gurus can shed some light on this. Will the spurred 4566 hammer fit a 4516 as a simple change-out? Is gunsmithing in order? Am I nuts to consider this modification? I like being able to pull a hammer back with my own thumb. Thanks in advance.[email protected]