I always worry when a D2 is my last working car. A TVR as backup for the D2 is a whole new level of brave
I can recover that PS pressure hose if needed, by replacing the rusted bit with hose and a suitable fitting. The union actually looks quite good so if you soak that in evaporust for a while then WD40 it should come apart, and then the new fitting can be added. The front pressure hose can be left in one piece that way, and you don't end up with the annoying whine. If you have a competent local hydraulic hose specialist (ie not the monkeys at Pirtek!) then they could also do the same - the fiting is a DIN M16x1.6 60-degree cone without o-ring. Its quite a tricky thing to get hold of.
How are the crimps on the return hose? Those are also quite a common failure point - they leak even when the crimps are still intact, and the hose is a really odd spec so I re-crimp them and then protect the joints with heatshrink.