That being said, you might want to contact them and see what they can tell you . . . I have a 74 Duster360, factory sunroof car also. Would be great to find a source for parts for them !
Contact info at bottom of this thread. Only guy I know that makes a reproduction seal and he may have some rear weatherstrip also. I got this guy's contact info back around 2001 at Monster Mopar from another guy who had the only 1971 Hemi Charger R/T with a factory sunroof I believe.