I was going to suggest the plugged filter too, just because you can see fuel in the filter does NOT mean it is flowing THROUGH the filter! Been there done that!

Peter: can you get to that "sock filter" in the tank without removing it? I havn't tried yet, but as long as this car sat before I rescued it I KNOW there is crap in there! I was also wondering about whether it was possible to remove the drain plug in the bottom of the fuel tank and take out the sending unit and get a respectable "flush" this way? Heck, I may even be able to get my arm in there far enough to wipe it out with a lint free cloth. ( Please note LINT FREE) Tom