You're in quite the pickle.

Head vs. Heart = Need vs. Want

Head(Need): You need a reliable car that can get you safely from point A to point B. So go buy a toyota prius and have a reliable car with great gas mileage.

Heart(Want): You want your car back to its glory days. So do it. Buying a replacement car will always leave you with a sour taste in your mouth. 6k cheaper to buy a different one that doesn't have the same history wont be the same thing. It sounds like you have saved the money and are ready, but you are having a hard time handing over the money. Close your eyes, hand them your hard earned money and let go of that aspect. Only worry about the project. Of course we the reader will say "go buy the cheaper low mileage one" because we have no attachment to your original car.

What now: Go battle it out and see who wins. Head or heart, need or want.

Its a tough decision. Good luck. Hope you find the right answer for you.