Solutions are out there. It depends on how little or how much you'll settle for.
FWIW, my el-cheapo method has been to make a simple leather pad which I cut in a manner so it can be fitted over the comb and laced at the bottom. Then I repair to our range on a quiet day, select yardage and fire at a stationary clay bird placed on a steep bank. Spare pieces of leather -- running from thin to thick -- are then placed between the comb and pad until I get where I want to be. These pieces are usually 2-3 inches in width and are completely covered by the outer pad. Modest left-right adjustments are sometimes also possible with this set-up. Sometimes, too, at this point, I'll remove the inserts and sand/taper them to blend more evenly with the stock when the outer leather is laced tight.
I have two or three of these in use all the time. Granted, they disturb the aesthetics of the stock, but I find myself unwilling to remove them often because they get the job done.
