Bake has it covered pretty well, but I think he may be a little high on the cost of cutting a stock and installing adjustable comb hardware. Quotes run from about $200 to $325.
I don't believe a morgan adjustable pad directly affects the height of point of impact compared to the point of aim (how high or flat a gun shoots). What affects POI is a change in the relative height of the barrel's bore compared to the shooter's eye. By lowering a Morgan you raise the line of the bore the same amount as you raise one's eye.
Moleskin in effect does about the same as a lace on, but the lace on can be removed when one wants to shoot a flat gun and laced back on when you want a high poi as in trap. Bake is right on about adjusting for left to right, what he calls windage. The fancy term is cast off and cast on for moving your POI right or left.
Last edited by Dreaming100Straight; September 25, 2013 at 01:44 AM.