NEED HELP ASAP convertible header

You need a header panel from a 69-70 Mustang. the repro 65-66 will not fit. I have heard the Cougar is the same, but can't verify that. These are the only years that will fit. Not reproduced, not likely it ever will because of the low demand for that year. You need to find a good used one, without a lot of corrosion. When you find one, clean it well, then prep it properly and paint it. I use a light acid etcher and painted it with a POR 15 product for aluminum to keep the corrosion from coming back under the top material.