So I guess there are a few things I don't understand, so if you could please clarify:
It is not an original 350 HO car?
What was the ORIGINAL powertrain/drivetrain?
It now has a 400/TH400 with a 3.55 rear?
Do you have any documentation with this car?
Have you had it since '88 or '90?
What is the ORIGINAL color?
Are the more current pictures of it shiny or dirty?
Do you have any pics with the hood closed?
Posting a picture of the firewall trim tag and the VIN will go a long way to help your sale.
Dave