Opel Monza are very striking cars and have a bit of a cult following - especially the 3.0-litre models. Might be worth giving one of the club's a shout. You could try Autobahnstormers (www.autobahnstormers.org.uk/). But also keep an eye on the classifieds (classics.honestjohn.co.uk/cars-for-sale/search/Ope...a). You should be able to pick up a project within your budget, although not all parts are easily available so do your homework before you buy.