Nobody is jumping in here, so I'll see if perhaps I can help.
With conical bore pipes, Highland and Border for example, moving the reed up and down has a greater effect on the upper hand notes than the bottom hand notes. This doesn't happen, at least to the same degree, on the cylindrical chanter of small pipes. So, it take a great degree of movement to sharpen the top hand and the whole chanter tends to go sharp at the same time.
You could try sharpening the top hand until it's in tune by pushing in the reed, and then taping the bottom holes as needed to bring them down a bit. Don't know that this will fix the problem, but you seem to have tried everything else.
The best answer may well be a new chanter reed...good luck with it!
Piper Joe