Floppy
There is an "auto-historian" who attends the XJS Seminars and covers the brochure/catalogue/handbook development of the marque (amongst others) and very entertaining it is! - comparisons of BL Allegro / Marina van and XJS brochures of the seventies are a hoot -unfortunately!
He has quite an extensive range of handbooks etc. for sale, and knows exactly which one is appropriate to your particular car.
Unfortunately I can't lay my hands on my Seminar programme and to my shame I CANNOT remember his name. I would suggest you ring Seminar organiser Nigel Thorley for contact details.
Re Carpets, I think you'll have to be very lucky. A few years ago there were rakes of original carpet sets at spares days but last time I looked they were like hen's teeth. Beware there ARE overmat sets available, do not confuse the two. There is a company in Wales who attend spares days who will re-manufacture carpets but I thought they were rather dear - £100+, plus VAT each item. I guess if you've got a concours car with dodgy carpets its a good investment.....but that's a bit of a contradiction in terms.
Best of luck in your search.
DH Dove