Generally, when I inlet a trigger plate, I slope the rear of the metal to fit in a slope cut in the wood. No need for another screw this way, and helps hide the back a bit. I also usually have the front of the lock plate, about 1/8th inch under the front of the trigger guard. This requires filing a notch in the trigger plate to accommodate the front of the trigger guard. This may seem like extra work, but it does make for a very solid trigger assembly.
Matt