Hi Stephie,
Actually the wiper,if I recall correctly, was the center, but like I have mention above due to the construction of the track, it will appear that the whole resistance of the pot is concentrated on one half side of the track which will appear that the actual use of the center will be the same effect if you use the side pin.
I think with your implementation of using fixed resistor you got it right the first time and I have mine into split which causes the lost of gain.
Not really important right now where the actual pin is as long as yours working and mine too, I'm happy.

ciao
Rom