Roger, good eye. What I do is this. The lockplate side is perpendicular to the top of the barrel.The sideplate side, however , is tilted in "slightly" toward the bottom. You can't actually see this. If the side plate side is laid flat and drilled , the screw holes will be lower than on the lock side, yet the heads will be flush. The sideplate will this be lower to the bottom line of the stock, and in my eye, more attractive. The top side bolt will be a little lower and thus the top edge of the lock panel can be below or level with the line where the oblique and side flat of the barrel meet. This creates gracefull lines. Many original makers did this. Forney does not and his sideplate panels are widet and a litle clumsy. The only thing I don't like about his rifles.
I rarely hit dead center with the web on the forward lock bolt. I like to err on the up side.
I hate scooping the bolt or making the rod to skinny. Who cares if there's a slight scoop in the bottom of the barrel.