I made my boy a shirt! And it (mostly!) fits. And he likes it. A good deal all around, though I will admit to wishing I'd used a pattern with a back yoke, so that I could more easily enclose the raw seams of the collar. Oh, well - I made it work. The inner facings are finished with bias tape (white), and the armhole seams are as well. The shoulders and side seams are french seams, so there are no raw seams in this garment. Woohoo!
Unfortunately, it is bordering on too small, so the next attempt will not yet be the dragon fabric. Instead, I'll try size 5 in another stash fabric that DS#1 picked out.