Need to mount Kef 3005 front speakers on side wall?

[J.C]

I've just bought a new TV which will mean I can't have my Front Left & Right Kef's on the little shelf below my TV anymore.

So what I want to do is mount them on the wall either side but the wall brackets won't allow for this.

I know this isn't very clear so I'm attaching an old photo. The TV is now bigger but I want to attach the left speaker to the chimney stack and the right speaker to the opposite wall.

Can anyone offer any advise?

Photo: http://i1109.photobucket.com/albums/h437/Jcleme/HC.jpg
Floorplan: http://i1109.photobucket.com/albums/h437/Jcleme/LivingRoom.jpg