Your best bet is to contact the Vauxhall Cresta club (www.vauxhallcrestaclub.co.uk/) - they'll be able to point you in the direction of a member who has some experience restoring these cars. As for parts, there's always eBay or one of the Vauxhall specialists like Green Parts (www.vauxhallgreenparts.co.uk). Restoring an old car is a labour of love that requires much time and money to be invested. Go into this project with your eyes open, though. Depending on how far gone the car is, you're unlikely to get your money back on the restoration - but restoring an old car goes beyond those constraints and is what makes our hobby great.