You can sell it and the parts as is, and MAYBE break even,
Or you can finish it and MOST LIKELY NOT break even.
A buddy here in Denver sold his orange '70E for about $30K two years ago, and it was perfect, with sport seats in original plaid.
Your car, 'perfect', with a 901 would not get $30K, since it's supposed to be a Sporto.
Unfortunately, your car, "perfect", with a sporto, wouldn't get $30K, because it's a Sporto. Catch-22.
IMO the real question is "Do you want to spend a year or two finishing this car that you already know you don't want, with a 100% chance of losing money?"
If you know you're going to lose money, lose it on the perfect car for you.