Sorry for not leaving this one to die a natural death..............
One thing I didn,t mention when trying to diagnose the failed pump which might save someone grief..............
When the engine was idling, the heater worked fine. The dribbler, piddler, or whatever it is called, to the spherical coolant bottle also was running fine.
But when the engine was revved to above 2000 rpm the hot air from the heater went cold, and the coolant return piddler stopped.
It seems that the slipping plastic impeller can catch back on the shaft at low rpm which can make diagnosing tricky, as you can't rev the engine on your own with your head stuck in the engine bay. Unless you have help, or a couple of bricks on the accelerator pedal.
Thanks to the tow truck guy knowing about this, saved me a lot of grief. He well earned his beer tokens.
My GUESS is that IF you are careful, keep the rpm to a max of 1500, WATCH THE GAUGE, not climbing steep hills, and the impeller decides to be nice to you, you might be able to limp home with it. Best of all have hot air coming out of the vents, the moment that goes cold, the impeller is slipping again, and you have run out of luck. PARK UP, and get towed.