I found this on a small and inactive Yahoo group for Sovereign sailboat owners. I can't vouch for its accuracy but have no reason to doubt it either.
I found someone connected to the manufacturing of the Sovereign. I am posting what he wrote to me.
Fred: In 1976 I was line foreman for the Buccaneer line of sailboats built by Bayliner in Valdosta, GA. We were building the Buccaneer 20, 24 and 27. I was so ashamed of the boat I was building I moved to The Tampa/St. Pete area of Florida in 1977, and started looking for a better quality boat to build. I hooked up with the three owners of Southern Sails of Largo, Florida who wanted to begin construction of the Skipper 20, but had no boat building experience. I built their prototype boat so they could start marketing it, and proceeded to hire the folks needed and set up the assembly line so we could start turning out the Skipper 20's.
After about a year the Skipper 20's were moving down the line smoothly and were selling well. The owners (I can't remember their names, it's been a while!) wanted to build a larger boat, but starting a hull from scratch was going to be very expensive. They acquired a set (deck and hull) of old S-2/ 7.3 meter molds and modified them to create the Sovereign 7.0. The start-up of this model caused disagreements among the three owners and cash got very tight, so then there were two companies. That is when the Sovereign Yacht Company was formed. We started production of the Sovereign 7.0 and worked on getting the bugs out of the assembly line. The owners wanted to build a solid boat and quality control was good. For a while the Skipper 20 and the Sovereign 7.0 were built at the same facility in Largo, Florida; and then Southern Sails moved out as Sovereign Yachts started expanding.
By this time, I has been in a fiberglass production environment for a number of years and kept thinking this had to be bad for my health long term, so I started looking for other areas of the marine trade that I would like. I became interested in selling boats instead of building them and left the company. So I was with them for the Sovereign 7.0 start-up, but had left by the time they introduced the 5.0. I do not know what eventually happened to the company and molds. The three original owners were all sailors. One had a naval architect background, one had a sales background, and the third had the capital. The relationship between the three was pretty good, and even the division and forming two companies was amicable. By the time they started building the 27' model I was out of touch with them as I had moved back to New England.
The connection with S-2 was simply the purchase of the molds. There was much swapping and selling of molds back then as boat companies kept going out of business and their molds would be up for grabs. I hope all this helps you. I'm pretty sure I have on original brochure for the Sovereign 7.0, although it would take some looking to get my hands on it. I could probably scan it and send it to you if you like. Let me know if I can do anything else for you.