I am going to give a wag. Now the guts can be seen, I suspect a single cabinet stereo system similar in concept to the JBL Paragon and what is throwing all off is there are 2 of them. I agree the pair may have been sold together for a quadrophonic system, One in the front and one in the rear.
The setup looks interesting. As it is not a sealed box probably the rca jacks should not need an issue as they were used to connect to some lower end amps eliminating the need to screw wires with the possibility of a short. You may want to just put a cap over them to eliminate an air entry port but not likely needed.
Have you hooked them up to try? Or held off scratching your head. You may want to consider, as you have a pair hooking the system in each box in parrellel, some call this stacking and standing them vertically and then connect each system to the amp and give it a try. Because of the layout I do not think it will do well but, nothing lost or gained by trying.
And interesting find and hope you locate some history. As you found another pair locally the manufacturer may have been local. Sometimes these oddity finds lead to some interesting outcomes. If you think you may,keep them, see if you can grab their from the other guy who trashed his just for the parts. The woofers may be difficult to sorcery as well as the horn drivers.