if you can do sheetmetal work you can buy a cheap coupe and order the fastback roof, quarter panels trunk sail panels tail panel etc from dynacorn and make your own for a fair price that is if you handy with a welder welcome kick back, post and hang out
You can also try to bring on of your Range Rover to Canada, they are very popular here and you might be able to exchange a Range Rover with dents for a Mustang fastback with holes
Used Cars for sale - Ford Mustang classifieds