This website is pretty much centered on the mk7 and mk7.5 Fiesta built in Mexico. The generation one Fiesta was only offered in three trims and with just one engine from late 1977 until just after 1980 in America. None of the versions were available with the sill extensions and wheel arch flares. I Cannot recall ever seeing that sort of item installed on an American fiesta, either in Aftermarket or owner acquired- installed. Anything like an XR2 "kit" installed on an American version of the Fiesta is beyond rare.