This is all correct I'm sure, and you actually know more about this aspect than I do! I would add that though the copyright is held by Thomas Nelson, Inc., and some of the aids ("People of the Bible," maps, etc.) are the property of Nelson, distribution was originally done by Anchor Bible Concepts, which has their name on the spine. This was run by Johnny Stancil at one time, I believe. I haven't seen him in years and don't know what happened to the company. They also produced the excellent Classic Note Bible. I don't believe the SOTL itself had any direct connection with the original publishing.
What makes it the Rice Reference Bible is the notes. I was privileged to help a little in the preparation of the notes when I worked at the Sword in 1976-1977. Granddad would hand me his handwritten notes on the historical books of the OT and I would type them up for him. He typed by the hunt and peck system, and what is amazing is that he would actually write books this way, though many of his books were dictated. For a sample of his handwriting, see the sermon notes on my website.