It should be relatively straightforward to do with a former and layering up thin pieces (we did it with veneer and PVA at school, many years ago). For the shape I think you'd need to have a three piece former - one for the inside, then cut the outer former along the top so that it can be put into place from the sides and clamped, rather than having to slid in from the front. Obviously that can be cut from a single block of wood - make the cut in the shape you want the finished piece, then cut the top piece along the top.