Jeff,
I've adjusted your illustration abit to show how our inner ribs are made.
The red lines are the alubox, the blue lines are the two 45 x approx 12 mm stringers wich fit on top and bottom of the box, (they are shaped to the countour of the airfoil}, green are stiffeners also fitting the box.
The web is 1.2mm birchply.
This is al set at 0 degrees. In the middle is ofcourse the dividing line.
Al of this is coverd with 2mm birchply. There's no stringer at the trailing edge the ply is only glued. At the end the whole is coverd and becomes very solid don't worrie. And the fit secures it's always put on right. The end ribs are 3mm birchply. I donn't understand the big cutout on allot of drawings because the wing is slid over the axlebox from the front and the back and the bugeecord and landinggear box are between these ribs. Our end ribs only have rectangular cut outs for the axle.
Willem