Id say 12K - 15K. Your car is very well done. I understand most want at least some of their money back. You may be able to get 14K or 15K for yours out your way, CA I mean. People have more money in that part of the country. Most Ive seen for sale in your cars condition are at least 11K or 12K. I hope you get what you want.
Proud owner of a White 1990 Twin Turbo w/90K original miles.