Could go really wrong if ordered from E-bay.   Unless from US or UK.  Australian ebay suppliers generally have it in 1.51M   widths,  and that is not wide enough for a D1-D2 disco,  due to high roof.  Need about 1.64M  width  (not sure).  Ask me how I know?
I ended up getting something called, 'Montana felt' , 2M width,  used in buses etc.   No foam backing to fail and looks much the same,   limited colours though.
Check the width of what he's ordered before tearing it all out.
found this really useful when I did mine.
 
Headliner Replacement step-by-step - Land Rover Forums - Land Rover Enthusiast Forum