\'89-up Thunderbird rear seat belts

I want to install 3 point seat belts into my 1966 Fairlane. I was told the T-Bird belts may fit my need. I want to be able to secure my daughters booster seat and her. I'm looking for a seat belt where the retractor is fastened to the top of the package tray. does anyone have a picture of their interior looking at the package tray and retractor? That is if the retractor is mounted on the package tray. I never looked in detail at the interior of those Birds.

Thanks,