It's the same torsion bar design used in dozens of cars from 6+ car manufactures. Google torsion bar and any info you find is basically universal (i.e. the concept is the same across the board).
Once you get your 100 crawl underneath and you will see all the pieces and components. Before getting my 100 (I came from a 80 as well) I was confused by torsion bar and though it was more complicated than it really is.
Hoser's pic explains it quite well. seems that the coilover concept is a great idea. Now I don't understand why that solution was dismissed. How could a flexy bar compete with a spring? A torsion bar doesn't inhibit the ability for the axle to droop?...seems it would. school me please.