1967/1968 Dick Harrell funny cars

Does anyone know if the Kirby car was from the same mold as Dick's 68 car? If so wouldn't the most direct comparison be a side by side of these 2 cars..I beleive (might be wrong)that car still exist. Also can someone tell me why Dick would have used the Kirby car if he had 2 cars in his stable...I believe it is generally accepted he drove the Kirby car in a few races if I'm not mistaken. The 2 car hypothesis works if a back up car is needed, but why would Dick need to use someone's else's car. Also are there any dates on any of the pics?