Kirbert,
Teves III is obsolete and no longer manufactured, same as the XJS. Everycar from the end of 80s/beginning of 90s was having ABS system based on hydraulic accumulator. These are all faulty by design, that’s why they’ve invented electric ABS pumps combining what’s the best of two aforementioned. Accumulator is design to supply sufficient pressure to stop the car, that’s why you have accumulators with various capacity.
None of the systems will effectively stop your car after brake hose burst scenario.
Now just imagine you’re doing 100mph on motorway and your engine dies - what happens? You have only power of your muscles, that includes power steering…
Teves has two separate circuits, the trick is that pressure from rear piston supports the force pressed on the front part of the master cylinder. It will still brake even with no fluid in rear wheels, but poorly.
We were having this conversation not long ago…