When I started to make the pattern for the body, what I had envisioned in the Secret Plan seemed overly complicated, so I simplified it to what you see here, and I think it's a big improvement. The most important part is that there are no side seams. The body is a tube that closes in the front and, along the top edge, attaches to the shoulder piece. This gives a relatively flat area for the arms to attach to.
To attach the arms, I used the cotter pins that I built into the arms. I glued a nylon washer on the inside of the body, cut a hole through the fabric at the center of the washer, and attached the cotter pin through that hole. The cotter pins that I used were too big. They were 1/8" in diameter, and so very hard to bend. Also, the bent ends of the cotter pins hang up against the stuffing, so the arms don't move freely like I wanted them to. I have an alternative in mind which would involve 1mm elastic plastic cording - like for stretchy beaded bracelets - and some attachment parts that I would make from polymer clay. So the next time I make one of these little figures I'll try that approach.
As I look at the photo I see that the tail is too long and too thick at the tip. So I'll have to correct that, which won't be difficult to do. I'll just remove the stitching along the lower third or so of the tail, remove some of the stuffing, trim the tail wire, trim the fabric, then re-sew, re-stuff, and re-close.