I am not sure if I am correct with this statement, so please someone correct me if it is wrong.
with respect to the ridges along the forearm (the “ladder like” area). I feel that those should line up more with your elbow than the top of your forearm. That way, the curve on the opposite side fits better into the inner aspect of your elbow when you bend your arm. Looking through screen references, some do seem to have the “ladder area” along the top of the arm, but I suspect they twist when moving about.
On your right forearm shot, you can see the curve is not in the area or line where your elbow will bend, which may be uncomfortable.
you can see in the photo below, the inner and outer aspects of both forearms.