Spitfire Houndstooth Seats

I was wondering if someone would be so kind as to help me locate the correct Beige houndstooth fabric that was used on the 1977-1980 triumph spitfires.

I've seen the seat covers that are made by Newton Commercial and the houndstooth fabric is a perfect match. Only thing is the beige vinyl is a very bad match. Please picture:

It seems that all of the suppliers like Rimmer Bros, Moss Motors, British Victoria all sell the Newton Commercial kits. I purchased a set from Moss and I was disappointed that the beige vinyl did not match at all as you can see in the picture. The cloth houndstooth seat panels are a perfect match though.

My spitfire only has 14,000 miles and the only part of the seat that needs replacement is the houndstooth seat panels. I thought I would try contacting Newton Commercial to see if they would sell me a couple of yards of their fabric and I would have a local trimmer sew in new panels for me.

The response from Newton is that they won't sell the just the fabric to a retail customer. All they offered to do is sell me another set of their poorly matched seat covers.

I was wondering if anyone in this group knows how I could locate some of this material?

Best Regards, Rusty