To add to this discussion. I bought my December 65 Dearborn built convertible in 1977. It had the same fuel tank top insulation as 21.4 posted, or very similar to it. In 2013 I bought my October 65 Metuchen built convertible from the second owner. It had the same or similar insulation.
Both of my convertibles have the standard interior. Neither car is equipped with anything special. They are just several of many that Ford cranked out thousands of: 289 2bbl, auto trans, radio, WSW tires, tinted windshield.