Okay, after taking it all on board, here's where it stands...

I checked the filter at the fuel distribution unit and it was clean. I pulled the fuel pump relay and jumped the terminal. The pumps, or at least a pump was audibly running, but the car failed to start. I removed a line to one of the injectors and there was no pressure with the pumps running with the air plate depressed. I open the fuel line prior to the fuel distribution unit under the same conditions and the result was the same, no pressure. When I checked pressure there previously (before my first post) with the relay in place and turning the engine over there was some pressure. Not a fountain, but some, but now there is none.

I suspect, unless there is a severe blockage in the line between the filter and fuel distro unit, the pumps need replacing as the next step. If that doesn't do it, I'll be back for more.

I'll also see if I can find a fuel gauge to measure the pressure.
Dan