I drove that very Sportwagon when looking for a 156 a couple of months ago, and thought it was ok! It does have rather a lot of swirl marks in the paint though, particuarly on the rear quarters and front wings/bonnet area! So Have a good look at it closely!!
(Obviously with a day of paint correction it could look a lot better, so maybe worth using that in your negotiation?)
Also check the disc's and pads for wear, tyre tread depth (mis-matching tyres) and alloys for curbing as most of the stock has one or all of the above issues.
He did have a silver 2.4 20v SW which was nicer, which I must admit I was more interested in at the time, although very over priced even with £800 off after haggling! I walked away in the end and bought my current Sport... (He sold it recently I think)
He does seem to have the UK's lions share of facelifted SW's at the moment, but as said above he does seem a tad expensive. I think the owner's called Carl and he will do a deal if you push him for a discount, and he seemed honest and pleasant to deal with... One other thing to watch... He uses a local garage to change the cambelts, but doesn't change the water pump!!
Hope that helps fella