I recently learned about this case and found something interesting. I've done a little lurking and found a blog link from the previous thread. There has been a lot of speculation about the Rebekah School in Corpus Christi as a possible location from which WCJD may have hailed.
From the prior thread:
The Night Wind: THANKSGIVING PSA UPDATE: PLEASE READ AND SHARE
The still frames in this blog are taken from a video produced at the school supposedly between 1978 and 1979.
Freedom's Last Call produced by Roloff Ministries.
It's not particularly reliable, but I isolated the two stills of the lookalike to WCJD and compared both against the two postmortems as well as the photo of Cathy/Kathy zoomed into the face using some free online facial recognition software, Betaface.
The stills from the video were 76 and 77% matches with the postmortems. What's interesting is that the two postmortems compared to each other gave an 83% match to one another, and the two stills compared to each other gave an 84% match. These are all incredibly close considering that comparing two photos known to be of the same person are in the mid 80% match range. The photo of Kathy/Cathy did not break 70% match compared to any of the others.
I know that people have reached out to alumni of the Rebekah School, but the existence of this video and the stills of the girl with a strong resemblance to WCJD and similar hair color, may help to narrow down the time frame of when pertinent records may have been kept. I'm not sure if there are any records from the school still available, but if so, maybe this could provide a starting point?