As far as the radius cut of the beavertail, some are practically drop-in but some are not. I've installled 2 or 3 on Kimbers. Twodropped right in with not fitting, but the 3rd took some fitting. However, all three needed fairly extensive blending of the frame to the beavertail.
Just food for thought...I have 1911s with a speed bump and without . I prefer the Colt/Kimber CDP arrangement . Ever since I developed a proper high grip I have never had a gun refuse to fire due to the grip safety not being engaged , however I HAVE had a REALLY sore hand from shooting different guns with pronounced "memory grooves" . I'm one who believes that JMB had it right in most instances ...Tom