Could be oil pump, was a recall on them, but it could also be the turbo falling to bits, call a dealer, ask if there are any recalls on it, or pm me the vin and or reg and i'll look for you
I'd be happy to come give some friendly advice, only live in Quedgely now and more than a few defenders and old discos,
BTW BB if you see another D1 (pref 300tdi) on your travels I'd like another, yes the old one nearly took my life but mechanically it never let me down :)
606688 x4
but thats fronts only,
if you have drums on the rear i have no idea but as 110 i dont think there are any shims, but you may need to change teh pad return springs and pins
do you have cornering lamps fitted (factory option),
failing that, as above, clean up the bulb hold conections (sand paper and a flat head screwdriver)