It's alive again.
Took about 2 1/2hrs to swap the pump and once primed she fired up first turn.
Running well if not down on power as the pump has not been tweaked, yet.
Thanks for the lone of the pump tool Julian, it made the job much easier.
Inlet banjo was clean, I think the gunk in the sedimenter maybe down to my off roading, as the tank breather is only 60cm off the ground, not good for deep(ish) water, this maybe what killed the pump but I'll pull it apart and see what the problem is, when I get time.