might have missed something here but if the top hose is hot and the bottom one is cool could it not be a radiator blockage???
because the temp sender is on the top of the block that would account for the high reading.i would take the rad off turn it upside down and run a hosepipe thro the bottom hose,might not work but at least its free, give it a good shake as well its amazing the amount of crud that sits in a radiator