grosbeck get the skin, sheeting on those edges before you drill them and be very accurate with the location marks If you redraw the profile end view you can see how much angle you have to work with, try to make it a bit more than a 45%. Take one of your hinge points and see how much it will bend to help give you an idea about the angle needed. Glue the guide blocks so they fit the angle nicely, 3/4"x1.5" makes a good guide depth, set it on the structure and mark the angle that will set the hinge head in the right place on its edge, also mark the center top of block for center alignment when you drill the holes. The angle doesn't have to be the same on both sides but the hinge pivot does. Hope this helps.

Leroy