The arched entry door - Minster, Oh - Core construction

I've started construction of the frame of the core. The edges of wood entry door frames can be visibly seen, and creates the outermost shape of the door. Once I make this frame, I will be filling it with staves (see previous post). This will eventually become one solid piece, and very resistant to warping. In these pictures, I am gluing up the side vertical rails of the frame, as well as some material to cut the arch from.
Why not use one solid piece for each part of the frame? Because if I mill separate pieces together, it will further the structural integrity of the door and give further resistance to warping. I am also using all the same type of wood for all parts of this door, so that all parts will expand and contract at the same rate. This means that even the interior core of the door is made from white oak!
I should have some pics of the assembled core frame in a day or two...