I've done something similar to this; the pleat/spiral folding is identical. What I would like to know is how you get the flat edges. Do you have instructions you could share? Excellent work on the spiral portion too; when I fold one out of larger paper it's difficult to get those angles just right. Sometimes I'll cheat and use a ruler to help.
My computer with the favorited site is not working right now, and i cannot find the url. I think you could figure it out easily enough though. This model is meant for a normal piece of computer paper. start with the short end facing you.fold it into 16ths up and down, then fold each of the 4 corners in so that it touches the line of the first 16th. The size of the flat part on the sides is the width of the folded in corner. I will try to find you the url, but that is how you would start.