So, who noticed the deliberate* mistake in the plans? Well if you did, write to me to claim your prize!
After adhering print-outs of the plans to the spoons, I cut out spoon one (as laid out pre-assembly above, with spoon two similarly arranged below it) and then drilled and began to cut into spoon two. And in the second round of saw-peircing, I noticed that the circuit that I was seperating from the main body of the spoon had no holes marked on the drawing, and therefore no holes drilled through the piece. By then it should have had both. So I got out the old texta, marked eight appropriate spots, and went back to the drill press.
*deliberate = complete, absent-minded omission