assuming its a digi, there are 2 seals per injector. rail is held onto head with allen bolts, then injectors are held into the inserts by friction alone. a leak like you describe could be down to the fuel rail itself, so if it was me i would buy a spare rail and rebuild that, then swap it over.
actually I would start by checking both the fuel lines to the rail, make sure they aren't perished. usually they crack at the ends, if so chop around 5-10mm off and refit with new fuel clips. if lines look really bad then replace, can be tricky to get the routing right, one of them is bent into an S shape. I managed with tweaking and strategically placed clips. make sure they cant rub on anything though!
