Dave, There are a variety of treatments and these are school and maker specific # 1, Is the most often seen slightly convex treatment from the tang to the top of the sideplate molding, This leaves a straight drop off to the breech of the barrel, not the most artistic treatment but frequently used. #2, Would be the same with straight drop off eliminated by angling the wood down to the breech of the barrel. The angle usually extends back 1/2-3/4 inch" and is more pleasing to the eye. This angle can be convex or concave. The third is the drop off from the tang to the sideplate is concave and is carried forward to intersect with the barrel on much the same level as the barrel. I hope this makes sense. I am sure others will come up with variations of these three basic treatments, but that is about it. Originals rarely left much wood proud behind the breech end of the barrel