I got an articulated female figure body from eBay and Opal is the closest color match. I had mixed feelings about switching Opal's head to the new body because I like Opals old body and the fact that she's thicker than other dolls. But articulation wins! So here's the new Opal:
Opal's original dress and panties fit the new figure. Her shoes are slightly too small (but she's working them anyway).
She is so much fun to pose.
Luckily, I managed to get Opal's head off without ruining her old body, so if I want to switch her back at some point, I can. I did not make any permanent modifications in order to get her head to fit her new body.