A too small grip has the fault of driving the nails into the ball of the thumb; it should be just thick enough to avoid this, any thicker would be clumsy.
An ivory stock is heavy, but this may be an advantage if there is weight needed in the stock to counterbalance the barrel, otherwise ivory gives a good grip, if roughed.
The depth of the roughing depends on the tenderness of the hand of the shooter.
A roughing which would make one man’s hand sore is hardly enough of a non-slip hold for a man whose skin is harder.
Sometimes screw heads and pins are not quite flush with the stock and may chafe the hand.
They and any roughness left on screw heads by the unskilful use of the screw driver should be filed down smooth.
A sore hand which gets hurt at each shot is very detrimental to good shooting and the shooter is constantly trying to get a fresh grip in order to save his hand.
Automatic pistols have almost universally a projection over the hand between the thumb and the trigger finger for the slide to work on.
This turns the stock into a “saw handle” which used to be common on English duelling pistols.
I have tried such a stock with very good results on a revolver, but it is in the way of one-handed cocking.