I'm writing a novel and need help with one tiny aspect of the story. One character owns two Caddies. A '59 convertible and a '59 coupe. I want them to be a matching pair, bought as a pair by the first owner, but how close can they be if I'm to stay real? Can I have them both silver with red interiors? Can they both be the same model (eg Eldorado)? When the factory built them, were they all built on the same production line? If so, can a coupe and a convertible have consecutive serial/vin numbers? I'm afraid I know my Corvettes much better than I know my Caddies, but I'd like to get this aspect of my story correct (for all the real Caddy fans out there). Any help is much appreciated.