Welcome to the forum Andy (I love those wide wheel arches on the Escort)
The one main difference with the S2 as compared to other 944 is to make sure your camchain and tensioner slipper have been checked or replaced at some point.
This is totally seperate from the cambelt and balance belt, it is a chain that connects the two cams together. There is a plastic slipper on the tensioner that gradually wears into two grooves from the chain. Ultimately the tensioner cannot maintain the correct tension, then the chain stretches and the sprockets on the cams can get rounded off [

] £££££ It can also snap which is even more £££££££££
Porsche have never, ever added this into any regular maintenance plan [

] so once cars started to reach around 10 years old or anything over about 80,000 miles we started to see problems. Most independant specialists know all about this and will change the slipper and chain for around £200, or the complete tensioner for a few hundred more. [

]
Or do it yourself here: [8D]
http://boerger.golden-tech.com/images/cam_chain_tensioner_replacement.htm
Berlyn Services run by Bert Gear the 944 tech Rep. supply a kit with all the bits and a new cam cover gasket for about £30