It was always my impression that the reconfigured grip was designed to reduce recoil.
I, too, own an original Colt Bisley, 5 & 1/2" in 38-40, circa 1900. Needless to say, I have never fired it. Just wondering it that redesigned grip did, in fact, reduce recoil to the extent that one could consider it a "target pistol" (as Colt designed and marketed it as such).
As an aside: THe Bisley Colt was Pancho Villa's sidearm of choice.