I have a '75 Duster, deep sherwood green, green interior, 57,000 miles. It's mostly all original, the interior is mint, except for the lumpy, saggy, loose headliner. I've noticed that resto parts places have both a bow type fabric replacement, plus a version similar to the original fibreboard, but made of modern materials. Anyone have a recommendation as to which to get? Is it difficult to install the board type yourself?