Frank, do you have books for the car? If you were to sell it i would rebuild the standard motor and get it back as close to standard as possible.
The vehicles you have seen going for big dollars are mint units like Bobs maroon one above (with 50kms on it).
These cars will shoot up in value in another 10 years, where they go from there is anyones guess. If the cash is not a problem Id just remove the fluids, stick it up on stands and leave it be.