Despite getting distracted by the intriguing discussions on this wonderful forum every time I come in for coffee, I managed to make some progress this morning. The top frame is made with bridle joints. The frame pieces have some of the edges rounded over on the router table and some corners knocked off with a sander to leave a rough form. The red pencil marks are put on during the dry fit and act as guides or limit lines.
A few swipes with each of a selection of three rasps/files then gets me here.
Some approximately 1" by 12" strips of 180 and 220 grit sandpaper lets me approach the final shape.
Some 320 grit paper gets me to the finished shape I am after.
Some 400 grit to finish up the end grain gets me to the soft but exagerrated joint I am after.