That may work. I can check out the 5 x 5 focal squares to see if I can cut them down, along with the triple rails, which are cut to 2 x 2...My math skills are going to be stretched to the limit here, I think...Ha! ha!
Do you get the feeling there may be something not quite right with the instructions, that it calls for the 5-3/8" triangles which are supposed to match with the focal squares being cut to 5 x 5"? Is it just me, or does this just seem WRONG?