Delighted to say that the ABS is now fully functional! After replacing the pump, module and ECU, plus reluctor rings and associated bits, it turned out that the wiring to the wheel sensors was the wrong way round i.e. left went to right wheel sensor and vice versa, apparently going back to when the car was built....
One bonus to it all is that there is now a red hood light showing on starting the car- it's only there briefly after flashing on and off a couple of times but at least there's a sign of life! I've tried to operate the hood but nothing happens and there's no further red light activity. Next thing is to check/replace the micro switches to see if that helps. Any ideas anyone?