here are some online catalogue links. they are invaluable for checking technical info, please add your own.
bosal exhausts : click (you have to search opel corsa A)
kolbenschmidt engine parts : click (this firm does loads of OE stuff & the catalogues have all manner of tech info on pistons, bearings & other engine parts, dimensions, drawings, model types etc.)
elring gaskets & seals they were the OE on novas : click
girling brake parts.. click
mintex brake pads.. click
valeo clutch... click
Mann filters... click
intermotor ign parts....click