S&S do a carpet kit so give them a call, it looks very simular to their kit.
A cheaper idea if you can be bothered is to go to the Triumph stonliegh show in February, and you'll find a guy there selling carpet for around a tenner which you could then cut yourself.
or even search the net for a local uphosterer who'll do the job for you.
[8 whole cylinders worth of punch to ram the world through the windshield and out the rear view mirror. Car & Driver]
1981 Grinnall TR7 v8
1981 Black FHC
1979 & 1980 Black Premium FHC(laid to rest) Sorry
John