Cleaned with cellulose thinners and closed with Realdoll adhesive. I took the staples out after 30 minutes, while the glue was still tacky.
Her neck no longer wobbles freely with a clunking sound. However, I realize it is not a proper engineering repair. A loop of wire is nowhere near as good a bearing surface as a steel washer. Nevertheless, if I take reasonable care of her I hope she will last another nine years before I have to repair her neck joint again.