Advice on saddle

noste500
noste500 Posts: 90
edited October 2012 in Road buying advice
Have just got a supersix and the std seat is giving me a sore backside.
To nail it down to the seat I swapped my seat of my old road bike and tried it . Result no pain.
Problem is I have sold my old road bike with the saddle.
The old road bike saddle is what looks to me a cheaper saddle ( brand is Active with a cut away down the centre )
New seat measures 134mm across the width and older one is slightly smaller on width and slight different shape.
Do I just need a narrower saddle do you think?

How do I get one the same as the old one?