OK, here goes.
Not disagreeing with you, Ian, but . . .
Measuring the grips on my Commander which is handy, I get .240" thick at both screw
locations, 1.510" wide at the bottom screw location, 1.265" wide at the top, perpendicular
to a line between the two holes.
Laying these out and fitting circles to them, gives me a 1 7/8" diam at the top, and 2 3/4" diam at the
bottom. If I turn a wooden cone to these dimensions, and then mill a flat on it, about
.010 - .020 below flush, then screw down a blank of the right width dimensions, with the
cone on pivots at the centers of the ends, mounted on a base with the edge lined up
with the surface of the cone, not the axis, this can be run up to a disk sander and
rotated to get a proper surface curvature, a nice and true cone. The .010 below surface
prevents getting sharp edges on the grips, and I might stop a little high, getting .260ish
thickness.
Overkill......no doubt. But, it would be neat to do.
Bill