Truckland,
Hope your in a nice area to be for a few days if nothing else. I think the relevant question is what is the actual failure? It could be an oring on a connection, I would ask if they verified the source of the leak and could tell you where it's coming from. Is it the inlet, the HP out to the rails, the return to the tank, or the body of the volume control valve? They may not even need a pump. It certainly did not have a catastrophic internal failure.
I also take the comment about getting to the pump with a grain of salt as this engine has obviously been designed using modern software for accessibility. The use of Cadmium plated fasteners and oring seals reflects modern design for maintainability. It looks to me that you would be staring at the pump in about an hour and a half.

It's interesting, I wanted to learn more about the LML Duramax for comparisons sake and found a video of the engine buildup and layout and the HP pumps look identical same 2 piston in a V configuration with the Volume Control Valve in the center.

Best of luck getting back out on the road.

Mark