Have a look in the focus rs room on the rsoc website.....loads of info on there about them mate
As said, good cars....i've only owned mine a few months after 6 years of rst ownership lol and haven't had to touch it so far, though it does have a very small water leak which i think is the thermostat housing ! Go well with a few mods (exhaust/decat/manifold/remap) and seem pretty strong motors!
Rust on the bottoms of the doors, underneath the wing mirrors where they meet the door and the other areas mentioned.
At 74k if it hasn't had a turbo or clutch you may want to assume that they may need changing in the near future, especially once you up the boost and remap!
Hope it's a good one, really nice cars to drive if you're used to old fords lol