Cutting the various pieces of wood to size on my usual home made jig.
These are the parts for the various basic box parts.
This will form the drop down part of the writing surface.
This will be the top opening part.
This will be the lower part and part of the writing surface...
.. and this is the three parts before cutting down to size. The upper part will rise to the left of the pic on quadrant hinges and the next section down will drop down to the right on strap hinges to make the writing surface.
Hope that all makes sense.
Roy.