It ended up taking three tries to make a box! The instructions are good, but I wanted to use PVA glue rather than glue stic. Things glued with glue stic tend to come apart. I have a few additional tips. If you are going to make one of these, plan on making two, in case you mess up the first one, like I did. I didn't use wallpaper, I just used some thin drawing paper. Fold the box all the way first, before gluing anything. I made three total (one I had to throw away). The tab on the first one had to be trimmed, but not the other two.
Fold the bottom flaps in different combinations to see which fit best. Then mark them with a 1 and a 2 (no need for #3, that's the last one). Some fit better going first.
I got confused with the first box and glued the two boxes together before inserting the tab. I was able to pry them apart, then reglue. This is my 'spare' box. The second time, I applied glue to the two squares, but then couldn't position the tab between two wet squares. This is the box I threw away. The third box was just right: I folded the box up and inserted the tab - DRY, no glue! Then, holding the box together, I pushed the glue brush in between the papers to apply the glue, on both sides. The squares didn't need to be completely covered in glue.
To apply glue to the bottom flaps, I had my glue paper (pages from old Martha Stewart Livings) at the edge of my art table, and held the box at the edge so that the flap only was on the glue paper, to brush on the glue. Below is a folded box and my notes for this blog post. (These notes are mainly for me, if I ever want to make an Orts box again.)
All three boxes. The one on cream paper is my original one, made in Seattle in 2000. A coworker gave me instructions. The top one is the wonky first one. I'll keep it at my art table for little bits of paper. The new one goes in my sewing container, to hold bits of thread while sewing.