Welcome to mud. A forum that respect honesty and integrity. One which the members help and look-out for each other.
To come up with a realistic value:
Post pictures of engine rebuild and parts used. Along with specifics of how and to what tolerances. Include pictures of part & machine shop receipts. This may add some value, certainly credibility.
If some body shop can do a quality body repair to RR and paint to match/blend, for $500, jump on it. It will add value. Post picture of estimate.
Replaced the missing seats along with other parts. Make it show room ready.
Bring all the PM items along with age and mileage related issues up-to-date and too factory spec.
Otherwise you've a story on a banged up high mileage 98LC with a screwed up engine. "Parts rig"