Seeing you post this made me go back and re-read your build thread(s) for Mental (MT.net seemed to have more pictures). I really enjoyed reading and watching in real time while you were building it. I can definitely understand why you would not want to sell it as a whole to someone with the "mental" amount of work and attention to detail you put into it. Ultimately though, you are the only one that can make this decision. Is it safe to say you enjoy the build process and creating essentially a piece of mechanical art more than the joy you get from driving it? If so, then it might be time to make the change. Maybe think about the Datsun as Mental reincarnated, if you were to chose to transfer some parts over. Will Mental get driven even less once the Datsun is finished?