I trust there's no option to get the TV up onto the chimney breast?
I'd put the centre on the stand directly central to the TV. I don't know for certain and I guess it would vary from person to person, but the dialogue from the centre of the screen visually, coming from a place to my left would jar.
Arcam A65+ & CD72T, B&W 602 S3, Grado SR125, QED S.A Biwire, Russ Andrews Classik Powerkords.
Sony KDL-V40A12U, Sony RDR-HXD910 DVDR, Onkyo TX-SR875, B&W MT-30 7.1, QED S.A XT & HDMI-P, Russ Andrews Yello power cables, Russ Andrews 8-way Silencerblock.