Andy, I have a note of the dimensions of the pipe Alex has, so just to make things fair please post the pipe you have which is subject to the size issue showing a ruler to confirm the two key dimensions.
I appreciate you may not be able to verify the pipe is infact yours, but it is unlikely to be another as this is the only bifurcated pipe Alex has been sent, and I am not sure he would send out a 'copy' intentionally which bares no resemblance to it.
There has to be an answer and solution, so the starting point is the measurements.......

marcs