Hank,I think you will come up a bit short on board width. We have been doing this for 30+ years and still draw a drawing or sketch of the ends of the boards when we do a custom wood bed. Leave 1/16 to 1/8 gap between the outer boards and the bedsides, then draw in your boards and strips. Leave 1/16 gap between the bedstrips and the adjacent raised part of the board. Original angles are 1-1/2 wide. Adjust the dimensions on your drawing until it looks like you want. You might even draw it out on a big piece of cardboard before you cut wood. Like you say, measure twice cut once.
http://www.mar-k.com/CustomForms/BedWood.pdf is a form that might help you lay it out. It will also help locate the cross sill holes for bed strips
Mar-Ktech
